High efficiency and mechanical robustness are both crucial for the practical applications of all‐polymer solar cells (all‐PSCs) in stretchable and wearable electronics. In this regard, a series of ...new polymer acceptors (PAs) is reported by incorporating a flexible conjugation‐break spacer (FCBS) to achieve highly efficient and mechanically robust all‐PSCs. Incorporation of FCBS affords the effective modulation of the crystallinity and pre‐aggregation of the PAs, and achieves the optimal blend morphology with polymer donor (PD), increasing both the photovoltaic and mechanical properties of all‐PSCs. In particular, an all‐PSC based on PYTS‐0.3 PA incorporated with 30% FCBS and PBDB‐T PD demonstrates a high power conversion efficiency (PCE) of 14.68% and excellent mechanical stretchability with a crack onset strain (COS) of 21.64% and toughness of 3.86 MJ m‐3, which is significantly superior to those of devices with the PA without the FCBS (PYTS‐0.0, PCE = 13.01%, and toughness = 2.70 MJ m‐3). To date, this COS is the highest value reported for PSCs with PCEs of over 8% without any insulating additives. These results reveal that the introduction of FCBS into the conjugated backbone is a highly feasible strategy to simultaneously improve the PCE and stretchability of PSCs.
New polymer acceptors (PAs) are developed by embedding flexible conjugation‐break spacer (FCBS) units into the rigid backbones. The incorporation of FCBS affords effective modulation of the crystallinity and pre‐aggregation of the PA and attains optimal blend morphology. As a result, the all‐polymer solar cells exhibit both a high efficiency of 14.68% and excellent mechanical robustness with a crack onset strain of 21.64%.
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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.
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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.
Narrow‐bandgap n‐type polymers with high electron mobility are urgently demanded for the development of all‐polymer solar cells (all‐PSCs). Here, two regioregular narrow‐bandgap polymer acceptors, ...L15 and MBTI, with two electron‐deficient segments are synthesized by copolymerizing two dibrominated fused‐ring electron acceptors (FREA) with distannylated aromatic imide, respectively. Taking full advantage of the FREA and the imide, both polymer acceptors show narrow bandgap and high electron mobility. Benefiting from the more extended absorption, better backbone ordering, and higher electron mobility than those of its regiorandom analog, the L15‐based all‐PSC yields a high power conversion efficiency (PCE) of 15.2% when blended with the polymer donor PM6. More importantly, MBTI incorporating a benzothiophene‐core FREA segment shows relatively higher frontier molecular orbital levels than L15, forming a cascade‐like energy level alignment with L15 and PM6. Based on this, ternary all‐PSCs are designed where MBTI is introduced as a guest into the PM6:L15 host system. Thanks to further optimal blend morphology and more balanced charge transport, the PCE is improved up to 16.2%, which is among the highest values for all‐PSCs. The results demonstrate that combining an FREA and an aromatic imide to construct regioregular narrow‐bandgap polymer acceptors provides an effective approach to fabricate highly efficient all‐PSCs.
A regioregular narrow‐bandgap n‐type polymer, L15, is synthesized, showing higher electron mobility and larger absorption coefficient compared to its random analog. When applied as an electron acceptor in all‐polymer solar cells (all‐PSCs), L15 yields outstanding efficiencies of 15.2% and 16.2% in binary and ternary all‐PSCs, respectively.
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Developing high-performance and mechanically robust polymer solar cells (PSCs) is crucial for realizing wearable power sources. While efficient all-polymer solar cells (all-PSCs) can be fabricated ...from polymerized small-molecule acceptors (PSMAs) with high optical absorption and electron mobilities, they still show limited mechanical robustness. Here, we achieve highly efficient and mechanically robust all-PSCs by designing a PSMA (PYFS-Reg) containing sequence-regular flexible spacers (FSs). The regular incorporation of the FS units into PSMAs is essential in simultaneously improving the electrical and mechanical properties of blend films. As a result, all-PSCs featuring PYFS-Reg achieve a high power conversion efficiency (PCE = 16.1%) and stretchability (crack onset strain (COS) = 22.4%), outperforming PSMAs without FSs (
i.e.
, PYBDT, PCE = 12.6% and COS = 11.7%) or with randomly distributed FSs (
i.e.
, PYFS-Ran, PCE = 12.2% and COS = 18.1%). Importantly, these all-PSCs are fabricated by an environmentally benign, non-halogenated solvent process. To further demonstrate their feasible applications in wearable devices, we construct intrinsically stretchable (IS) all-PSCs by using PYFS-Reg-based active layers, which exhibit a high PCE (10.6%) and excellent device stretchability (strain at PCE
80%
= 36.7%).
We report a new molecular design of sequentially regular polymerized small-molecule-acceptors containing flexible spacer (FS) units (PYFS-Reg) to achieve all-polymer solar cells with both high-performance and mechanical stretchability.
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.
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Intrinsically stretchable organic solar cells (IS‐OSCs), consisting of all stretchable layers, are attracting significant attention as a future power source for wearable electronics. However, most of ...the efficient active layers for OSCs are mechanically brittle due to their rigid molecular structures designed for high electrical and optical properties. Here, a series of new polymer donors (PDs, PhAmX) featuring phenyl amide (N1,N3‐bis((5‐bromothiophen‐2‐yl)methyl)isophthalamide, PhAm)‐based flexible spacer (FS) inducing hydrogen‐bonding (H‐bonding) interactions is developed. These PDs enable IS‐OSCs with a high power conversion efficiency (PCE) of 12.73% and excellent stretchability (PCE retention of >80% of the initial value at 32% strain), representing the best performances among the reported IS‐OSCs to date. The incorporation of PhAm‐based FS enhances the molecular ordering of PDs as well as their interactions with a Y7 acceptor, enhancing the mechanical stretchability and electrical properties simultaneously. It is also found that in rigid OSCs, the PhAm5:Y7 blend achieves a much higher PCE of 17.5% compared to that of the reference PM6:Y7 blend. The impact of the PhAm‐FS linker on the mechanical and photovoltaic properties of OSCs is thoroughly investigated.
Efficient, intrinsically stretchable organic solar cells (IS‐OSCs) are developed by designing a new series of polymer donors (PDs, PhAm) featuring hydrogen‐bonding‐capable flexible spacers. High power conversion efficiency (PCE = 12.7%) and stretchability (PCE retention of > 80% at 32% strain) are demonstrated, which represent the best performances in terms of both PCE and stretchability among the IS‐OSCs reported to date.
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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.
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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.
Oral microbiota can alter cancer susceptibility and progression by modulating metabolism and inflammation. We assessed the association between the oral microbiome and lymph node (LN) metastasis in ...oral squamous cell carcinoma (OSCC). We collected a total of 54 saliva samples from patients with OSCC before surgery. LN metastasis was assessed based on postoperative pathological examination. We used QIIME2, linear discriminant analysis effect size (LEfSe), and PICRUSt2 methods to analyze microbial dysbiosis. A random forest classifier was used to assess whether the oral microbiome could predict LN metastasis. Among the 54 OSCC samples, 20 had LN metastasis, and 34 had no evidence of metastasis. There was a significant difference in β-diversity between the metastasis and no metastasis groups. Through LEfSe analysis, the metastasis group was enriched in the genera Prevotella, Stomatobaculum, Bifidobacterium, Peptostreptococcaceae, Shuttleworthia and Finegoldia. Pathways related to signal peptidase II were predominant in the no metastasis group. The RF model showed a modestly high accuracy for predicting metastasis. Differences in microbial community composition and functions were observed in the oral microbiome of patients with OSCC with and without LN metastasis. However, the finding that specific taxa may be associated with LN metastasis should be verified in a further prospective study.
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