Transition-metal-catalyzed activation of C–H and C–C bonds is a challenging area in synthetic organic chemistry. Among various methods to accomplish these processes, the approach using metal–organic ...cooperative catalytic systems is one of the most promising. In this protocol, organic molecules as well as transition metals act as catalysts to bring about reactions, which proceed with high efficiencies and selectivities. Various metal–organic cooperative catalytic systems developed for C–H and C–C bond activation reactions are discussed in this review. Also discussed are how each metal–organic cooperative catalyst affects the reaction mechanism and what kinds of substrates can be applied in each of the catalytic processes.
Abstract
Perovskite light-emitting diodes (PeLEDs) based on three-dimensional (3D) polycrystalline perovskites suffer from ion migration, which causes overshoot of luminance over time during ...operation and reduces its operational lifetime. Here, we demonstrate 3D/2D hybrid PeLEDs with extremely reduced luminance overshoot and 21 times longer operational lifetime than 3D PeLEDs. The luminance overshoot ratio of 3D/2D hybrid PeLED is only 7.4% which is greatly lower than that of 3D PeLED (150.4%). The 3D/2D hybrid perovskite is obtained by adding a small amount of neutral benzylamine to methylammonium lead bromide, which induces a proton transfer from methylammonium to benzylamine and enables crystallization of 2D perovskite without destroying the 3D phase. Benzylammonium in the perovskite lattice suppresses formation of deep-trap states and ion migration, thereby enhances both operating stability and luminous efficiency based on its retardation effect in reorientation.
Conventional organic light‐emitting devices without an encapsulation layer are susceptible to degradation when exposed to air, so realization of air‐stable intrinsically‐stretchable display is a ...great challenge because the protection of the devices against penetration of moisture and oxygen is even more difficult under stretching. An air‐stable intrinsically‐stretchable display that is composed of an intrinsically‐stretchable electroluminescent device (SELD) integrated with a stretchable color‐conversion layer (SCCL) that contains perovskite nanocrystals (PeNCs) is proposed. PeNCs normally decay when exposed to air, but they become resistant to this decay when dispersed in a stretchable elastomer matrix; this change is a result of a compatibility between capping ligands and the elastomer matrix. Counterintuitively, the moisture can efficiently passivate surface defects of PeNCs, to yield significant increases in both photoluminescence intensity and lifetime. A display that can be stretched up to 180% is demonstrated; it is composed of an air‐stable SCCL that down‐converts the SELD’s blue emission and reemits it as green. The work elucidates the basis of moisture‐assisted surface passivation of PeNCs and provides a promising strategy to improve the quantum efficiency of PeNCs with the aid of moisture, which allows PeNCs to be applied for air‐stable stretchable displays.
An air‐stable stretchable display consisting of an intrinsically stretchable electroluminescent device and perovskite nanocrystal (PeNCs) stretchable color conversion layer is proposed. Surprisingly, the increase in photoluminescence intensity of PeNCs in the water is proved to be caused by the surface passivation of moisture, which overcomes the water instability of perovskite materials.
Recent advances in the power conversion efficiency (PCE) of organic solar cells (OSCs) have greatly enhanced their commercial viability. Considering the technical standards (e.g., mechanical ...robustness) required for wearable electronics, which are promising application platforms for OSCs, the development of fully stretchable OSCs (f‐SOSCs) should be accelerated. Here, a comprehensive overview of f‐SOSCs, which are aimed to reliably operate under various forms of mechanical stress, including bending and multidirectional stretching, is provided. First, the mechanical requirements of f‐SOSCs, in terms of tensile and cohesion/adhesion properties, are summarized along with the experimental methods to evaluate those properties. Second, essential studies to make each layer of f‐SOSCs stretchable and efficient are discussed, emphasizing strategies to simultaneously enhance the photovoltaic and mechanical properties of the active layer, ranging from material design to fabrication control. Key improvements to the other components/layers (i.e., substrate, electrodes, and interlayers) are also covered. Lastly, considering that f‐SOSC research is in its infancy, the current challenges and future prospects are explored.
A comprehensive overview of fully stretchable organic solar cells (f‐SOSCs), including essential studies to make each layer of an f‐SOSC stretchable and efficient is provided. Various strategies to simultaneously enhance the photovoltaic and mechanical properties of the active layer, ranging from material design to fabrication control, are emphasized.
Cerebral amyloidosis and severe tauopathy in the brain are key pathological features of Alzheimer's disease (AD). Despite a strong influence of the intestinal microbiota on AD, the causal ...relationship between the gut microbiota and AD pathophysiology is still elusive.
Using a recently developed AD-like pathology with amyloid and neurofibrillary tangles (ADLP
) transgenic mouse model of AD, which shows amyloid plaques, neurofibrillary tangles and reactive gliosis in their brains along with memory deficits, we examined the impact of the gut microbiota on AD pathogenesis.
Composition of the gut microbiota in ADLP
mice differed from that of healthy wild-type (WT) mice. Besides, ADLP
mice showed a loss of epithelial barrier integrity and chronic intestinal and systemic inflammation. Both frequent transfer and transplantation of the faecal microbiota from WT mice into ADLP
mice ameliorated the formation of amyloid β plaques and neurofibrillary tangles, glial reactivity and cognitive impairment. Additionally, the faecal microbiota transfer reversed abnormalities in the colonic expression of genes related to intestinal macrophage activity and the circulating blood inflammatory monocytes in the ADLP
recipient mice.
These results indicate that microbiota-mediated intestinal and systemic immune aberrations contribute to the pathogenesis of AD in ADLP
mice, providing new insights into the relationship between the gut (colonic gene expression, gut permeability), blood (blood immune cell population) and brain (pathology) axis and AD (memory deficits). Thus, restoring gut microbial homeostasis may have beneficial effects on AD treatment.
Objective
There is no scale for rating the severity of autoimmune encephalitis (AE). In this study, we aimed to develop a novel scale for rating severity in patients with diverse AE syndromes and to ...verify the reliability and validity of the developed scale.
Methods
The key items were generated by a panel of experts and selected according to content validity ratios. The developed scale was initially applied to 50 patients with AE (development cohort) to evaluate its acceptability, reproducibility, internal consistency, and construct validity. Then, the scale was applied to another independent cohort (validation cohort, n = 38).
Results
A new scale consisting of 9 items (seizure, memory dysfunction, psychiatric symptoms, consciousness, language problems, dyskinesia/dystonia, gait instability and ataxia, brainstem dysfunction, and weakness) was developed. Each item was assigned a value of up to 3 points. The total score could therefore range from 0 to 27. We named the scale the Clinical Assessment Scale in Autoimmune Encephalitis (CASE). The new scale showed excellent interobserver (intraclass correlation coefficient ICC = 0.97) and intraobserver (ICC = 0.96) reliability for total scores, was highly correlated with modified Rankin scale (r = 0.86, p < 0.001), and had acceptable internal consistency (Cronbach α = 0.88). Additionally, in the validation cohort, the scale showed high interobserver reliability (ICC = 0.99) and internal consistency (Cronbach α = 0.92).
Interpretation
CASE is a novel clinical scale for AE with a high level of clinimetric properties. It would be suitable for application in clinical practice and might help overcome the limitations of current outcome scales for AE. ANN NEUROL 2019;85:352–358.
Heterogenous electrocatalysts based on transition metal sulfides (TMS) are being actively explored in renewable energy research because nanostructured forms support high intrinsic activities for both ...the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, it is described how researchers are working to improve the performance of TMS‐based materials by manipulating their internal and external nanoarchitectures. A general introduction to the water‐splitting reaction is initially provided to explain the most important parameters in accessing the catalytic performance of nanomaterials catalysts. Later, the general synthetic methods used to prepare TMS‐based materials are explained in order to delve into the various strategies being used to achieve higher electrocatalytic performance in the HER. Complementary strategies can be used to increase the OER performance of TMS, resulting in bifunctional water‐splitting electrocatalysts for both the HER and the OER. Finally, the current challenges and future opportunities of TMS materials in the context of water splitting are summarized. The aim herein is to provide insights gathered in the process of studying TMS, and describe valuable guidelines for engineering other kinds of nanomaterial catalysts for energy conversion and storage technologies.
Heterogenous electrocatalysts based on transition metal sulfides (TMS) are being actively explored in renewable energy research because nanostructured forms support high intrinsic activities for both the hydrogen evolution reaction and oxygen evolution reaction. Ways to improve the performance of TMS‐based materials by manipulating their internal and external nanoarchitectures are described.
The imperative to electrify the transport sector in the past few decades has put millions of electric vehicles on the road worldwide with an extended mile range from critical technological ...breakthroughs in developing the rechargeable energy storage systems, which also covers electronic devices and smart grid applications. However, the available energy density of prevailing systems in the market (i.e., batteries) is reaching its boundaries due to the limited choice of electrochemical reactions that necessarily depend on the thermodynamics and kinetics of the components (e.g., cathode, anode, electrolyte, separator, and current collectors). Reaching the high energy density of batteries exploits new redox chemistry such as sensitive metal anodes, insulating and highly dissolving sulfur cathodes, etc., thus requiring novel designs of various multiscale functional materials to address the corresponding issues. Here, the recent achievements on the designs of smart functional materials for emerging problems in the whole range of systems are discussed: i) interfacial control/kinetic regulation of Li–S battery; ii) self‐healing‐driven structural stability in the electrode and electrolyte; iii) ion‐sieving functional membranes for selective scavenging capability; and iv) functional materials to ensure battery safety.
Smart, functional materials in the nano/microscale that are specially designed for rechargeable batteries are comprehensively discussed. The designed materials aim to address the issues in interfacial chemistry of Li metal anodes and sulfur cathodes, integration of electrodes or electrolytes during unusual deformations, selectivity of membranes, and safety of systems.
Background
With improved short-term surgical outcomes, laparoscopic distal gastrectomy has rapidly gained popularity. However, the safety and feasibility of laparoscopic total gastrectomy (LTG) has ...not yet been proven due to the difficulty of the technique. This single-arm prospective multi-center study was conducted to evaluate the use of LTG for clinical stage I gastric cancer.
Methods
Between October 2012 and January 2014, 170 patients with pathologically proven, clinical stage I gastric adenocarcinoma located at the proximal stomach were enrolled. Twenty-two experienced surgeons from 19 institutions participated in this clinical trial. The primary end point was the incidence of postoperative morbidity and mortality at postoperative 30 days. The severity of postoperative complications was categorized according to Clavien–Dindo classification, and the incidence of postoperative morbidity and mortality was compared with that in a historical control.
Results
Of the enrolled patients, 160 met criteria for inclusion in the full analysis set. Postoperative morbidity and mortality rates reached 20.6% (33/160) and 0.6% (1/160), respectively. Fifteen patients (9.4%) had grade III or higher complications, and three reoperations (1.9%) were performed. The incidence of morbidity after LTG in this trial did not significantly differ from that reported in a previous study for open total gastrectomy (18%).
Conclusions
LTG performed by experienced surgeons showed acceptable postoperative morbidity and mortality for patients with clinical stage I gastric cancer.
Abstract
This study investigates and proposes innovative approaches to achieve frequency selectivity within a limited space. Traditional multiresonant acoustic devices use individual sensing elements ...of varying sizes to achieve resonance frequency (
f
r
), leading to an inability to sense focused acoustic waves, unlike the human ear. A miniaturized, self‐powered artificial basilar membrane that incorporates multiresonant features is introduced. Multiple
f
r
of the diaphragms are developed using inner boundary conditions (iBCs) defined by an adjustable micropatterned elastomeric support (µ‐support) and a porous nanofiber (NF) mat. This new approach offers the advantage of all‐in‐one fabrication, eliminating the need for device area variation or an additional rigid frame typically required in conventional multiresonant acoustic devices. The efficacy of the iBCs in shifting
f
r
within the vocal frequency ranges is verified via a laser Doppler vibrometer, simulation, and triboelectric output. With its self‐powering capabilities based on triboelectric principles, this artificial basilar membrane holds promise for accurately recognizing musical and vocal signals with specific frequency characteristics. With four different iBCs in a total device area of 23 × 23 mm
2
, a tunable four‐channel system with
f
r
ranging from 400 to 3000 Hz is achieved. This advancement enables the sensing of focused acoustic waves, simulating the functionality of an artificial human ear model.
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