How does technological innovation fit with business model design to jointly impact firm growth? Given the increasingly salient role of business model, extant literature provides little answer to this ...question. This study builds a theoretical model based on technological innovation literature, business ecosystem theory, and business model literature to investigate this issue. This study finds that exploitative innovation and exploratory innovation fit with different business model designs to promote firm growth. Six hypotheses are proposed and examined by a database from 176 Chinese firms. This research finds that exploitative innovation has a negative whereas exploratory innovation has a positive effect on firm growth. More importantly, we find that efficiency‐centered business model design enhances the negative effect of exploitative innovation and weakens the positive effect of exploratory innovation. We also find that novelty‐centered business model design weakens the negative effect of exploitative innovation. This research contributes to both technological innovation and business model design literature.
Single atom catalysts exhibit particularly high catalytic activities in contrast to regular nanomaterial-based catalysts. Until recently, research has been mostly focused on single atom catalysts, ...and it remains a great challenge to synthesize bimetallic dimer structures. Herein, we successfully prepare high-quality one-to-one A-B bimetallic dimer structures (Pt-Ru dimers) through an atomic layer deposition (ALD) process. The Pt-Ru dimers show much higher hydrogen evolution activity (more than 50 times) and excellent stability compared to commercial Pt/C catalysts. X-ray absorption spectroscopy indicates that the Pt-Ru dimers structure model contains one Pt-Ru bonding configuration. First principle calculations reveal that the Pt-Ru dimer generates a synergy effect by modulating the electronic structure, which results in the enhanced hydrogen evolution activity. This work paves the way for the rational design of bimetallic dimers with good activity and stability, which have a great potential to be applied in various catalytic reactions.
The Li-rich, Mn-rich (LMR) layered structure materials exhibit very high discharge capacities exceeding 250 mAh g–1 and are very promising cathodes to be used in lithium ion batteries. However, ...significant barriers, such as voltage fade and low rate capability, still need to be overcome before the practical applications of these materials. A detailed study of the voltage/capacity fading mechanism will be beneficial for further tailoring the electrode structure and thus improving the electrochemical performances of these layered cathodes. Here, we report detailed studies of structural changes of LMR layered cathode LiLi0.2Ni0.2Mn0.6O2 after long-term cycling by aberration-corrected scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS). The fundamental findings provide new insights into capacity/voltage fading mechanism of LiLi0.2Ni0.2Mn0.6O2. Sponge-like structure and fragmented pieces were found on the surface of cathode after extended cycling. Formation of Mn2+ species and reduced Li content in the fragments leads to the significant capacity loss during cycling. These results also imply the functional mechanism of surface coatings, for example, AlF3, which can protect the electrode from etching by acidic species in the electrolyte, suppress cathode corrosion/fragmentation, and thus improve long-term cycling stability.
Over the past decades, supramolecular luminescent materials (SLMs) have attracted considerable attention due to their dynamic noncovalent interactions, versatile functions, and intriguing ...applications in many research fields. From construction to application, great efforts and progress have been made in color‐tunable SLMs in recent years. In order to realize multicolor luminescence, various design strategies have been proposed. Macrocyclic chemistry, one of the brightest jewels in the field of supramolecular chemistry, has played a crucial role in the construction of stimuli‐responsive and emission‐tunable SLMs. Moreover, the flexible and tunable conformation and multiple noncovalent complexation sites of the macrocyclic arenes (MAs) afford a new opportunity to create such dynamic smart luminescent materials. Inspired by our reported work on the color‐tunable supramolecular crystalline assemblies modulated by the conformation of naphth4arene, this Concept provides a summary of the latest developments in the construction of color‐tunable MA‐based SLMs, accompanied by the various construction strategies. The aim is to provide researchers with a new perspective to construct color‐tunable SLMs with fascinating functions.
This Concept summarizes the developments and advances in designing strategies toward macrocyclic arene (MA)‐based color‐tunable supramolecular luminescent materials (SLMs). Included discussions are those about metal coordination, stimuli‐responses, guest‐dependence, and conformation modulation where multiple supramolecular systems such as assemblies, host‐guest complexes, and crystalline materials are involved.
Abstract
Background
Reports have proven that shorter door-to-needle time (DTN time) indicates better outcomes in AIS patients received intravenous thrombolysis. Efforts have been made by hospitals ...and centers to minimize DTN time in many ways including introducing a stroke nurse. However, there are few studies to discuss the specific effect of stroke nurse on patients’ prognosis. This study aimed to compare consecutive AIS patients before and after the intervention to analyze the effect of stroke nurse on clinical outcome of AIS patients.
Methods
In this retrospective study, we observed 1003 patients from November 2016 to December 2020 dividing in two groups, collected and analyzed AIS patients’ medical history, clinical assessment information, important timelines, 90 mRS score, etc. Comparative analysis and mediation analysis were also used in this study.
Results
A total of 418 patients was included in this study, and 199 patients were enrolled in the stroke nurse group and 219 was in the preintervention group. Baseline characteristics of patients showed no significant difference except there seems more patients with previous ischemic stroke history in the group of stroke nurse. (
p
= 0.008). The median DTN time significantly decreased in the stroke nurse group (25 min versus 36 min,
p
< 0.001) and multivariate logistic regression analysis showed the 90-day mRS clinical outcome significantly improved in the stroke nurse group (
p
= 0.001). Mediation analysis indicated the reduction of DTN time plays a partial role on the 90 days mRS score and the stroke nurse has some direct effect on the improvement of clinical outcome (
p
= 0.006).
Conclusions
The introduction of stroke nurse is beneficial to clinical outcome of AIS patients and can be use of reference in other hospitals or centers.
Lithium–sulfur (Li–S) battery is one of the most promising energy storage systems because of its high specific capacity of 1675 mAh g–1 based on sulfur. However, the rapid capacity degradation, ...mainly caused by polysulfide dissolution, remains a significant challenge prior to practical applications. This work demonstrates that a novel Ni-based metal organic framework (Ni-MOF), Ni6(BTB)4(BP)3 (BTB = benzene-1,3,5-tribenzoate and BP = 4,4′-bipyridyl), can remarkably immobilize polysulfides within the cathode structure through physical and chemical interactions at molecular level. The capacity retention achieves up to 89% after 100 cycles at 0.1 C. The excellent performance is attributed to the synergistic effects of the interwoven mesopores (∼2.8 nm) and micropores (∼1.4 nm) of Ni-MOF, which first provide an ideal matrix to confine polysulfides, and the strong interactions between Lewis acidic Ni(II) center and the polysulfide base, which significantly slow down the migration of soluble polysulfides out of the pores, leading to the excellent cycling performance of Ni-MOF/S composite.
Graphene quantum dots (GQDs) have gained significant attention in various biomedical applications. The physicochemical properties of these nanoparticles, including toxic effects, are largely ...determined by their surface modifications. Previous studies have demonstrated high in vitro cytotoxicity of the hydroxylated GQDs (OH-GQDs). The focus of this study was on the intestinal toxicity of OH-GQDs. Briefly, C57BL/6J mice were given daily oral gavage of 0.05, 0.5 or 5 mg/kg OH-GQD for 7 days, and the indices of intestinal damage were evaluated. Higher doses of the OH-GQDs caused significant intestinal injuries, such as enhanced intestinal permeability, shortened villi and crypt loss. The number of Lgr5
+
intestinal stem cells also decreased dramatically upon OH-GQDs exposure, which also inhibited the Ki67
+
proliferative progenitor cells. In addition, an increased number of crypt cells harboring the oxidized DNA base 8-OHdG and γH2AX foci were also detected in the intestines of OH-GQD-treated mice. Mechanistically, the OH-GQDs up-regulated both total and phosphorylated p53. Consistent with this, the average number of TUNEL
+
and cleaved caspase-3
+
apoptotic intestinal epithelial cells were significantly increased after OH-GQDs treatment. Finally, a 3-dimensional organoid culture was established using isolated crypts, and OH-GQDs treatment significantly reduced the size of the surviving intestinal organoids. Taken together, the intestinal toxicity of the OH-GQDs should be taken into account during biomedical applications.
Chirality‐driven self‐sorting plays an essential role in controlling the biofunction of biosystems, such as the chiral double‐helix structure of DNA from self‐recognition by hydrogen bonding. ...However, achieving precise control over the chiral self‐sorted structures and their functional properties for the bioinspired supramolecular systems still remains a challenge, not to mention realizing dynamically reversible regulation. Herein, we report an unprecedented saucer4arene‐based charge transfer (CT) cocrystal system with dynamically reversible chiral self‐sorting synergistically induced by chiral triangular macrocycle and organic vapors. It displays efficient chain length‐selective vapochromism toward alkyl ketones due to precise modulation of optical properties by vapor‐induced diverse structural transformations. Experimental and theoretical studies reveal that the unique vapochromic behavior is mainly attributed to the formation of homo‐ or heterochiral self‐sorted assemblies with different alkyl ketone guests, which differ dramatically in solid‐state superstructures and CT interactions, thus influencing their optical properties. This work highlights the essential role of chiral self‐sorting in controlling the functional properties of synthetic supramolecular systems, and the rarely seen controllable chiral self‐sorting at the solid‐vapor interface deepens the understanding of efficient vapochromic sensors.
A chiral macrocycle‐based cocrystal system that undergoes dynamically reversible chiral self‐sorting displays efficient chain length‐selective vapochromism to alkyl ketones. The unique vapochromic behavior was mainly due to different solid‐state superstructures and noncovalent interactions from the homo‐ or heterochiral self‐assembly.
A powerful low-cost electrocatalyst, nanorod Nb2O5, is synthesized using the hydrothermal method with monoclinic phases and simultaneously deposited on the surface of a graphite felt (GF) electrode ...in an all vanadium flow battery (VRB). Cyclic voltammetry (CV) study confirmed that Nb2O5 has catalytic effects toward redox couples of V(II)/V(III) at the negative side and V(IV)/V(V) at the positive side to facilitate the electrochemical kinetics of the vanadium redox reactions. Because of poor conductivity of Nb2O5, the performance of the Nb2O5 loaded electrodes is strongly dependent on the nanosize and uniform distribution of catalysts on GF surfaces. Accordingly, an optimal amount of W-doped Nb2O5 nanorods with minimum agglomeration and improved distribution on GF surfaces are established by adding water-soluble compounds containing tungsten (W) into the precursor solutions. The corresponding energy efficiency is enhanced by ∼10.7% at high current density (150 mA·cm–2) as compared with one without catalysts. Flow battery cyclic performance also demonstrates the excellent stability of the as prepared Nb2O5 catalyst enhanced electrode. These results suggest that Nb2O5-based nanorods, replacing expensive noble metals, uniformly decorating GFs holds great promise as high-performance electrodes for VRB applications.
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