Proton‐responsive photochromic molecules are attractive for their ability to react on non‐invasive rapid optical stimuli and the importance of protonation/deprotonation processes in various fields. ...Conventionally, their acidic/basic sites are on hetero‐atoms, which are orthogonal to the photo‐active π‐center. Here, we incorporate azulene, an acid‐sensitive pure hydrocarbon, into the skeleton of a diarylethene‐type photoswitch. The latter exhibits a novel proton‐gated negative photochromic ring‐closure and its optical response upon protonation in both open and closed forms is much more pronounced than those of diarylethene photoswitches with hetero‐atom based acidic/basic moieties. The unique behavior of the new photoswitch can be attributed to direct protonation on its π‐system, supported by 1H NMR and theoretical calculations. Our results demonstrate the great potential of integrating non‐alternant hydrocarbons into photochromic systems for the development of multi‐responsive molecular switches.
Incorporation of an azulene moiety into a diarylethene photoswitch gives rise to unprecedented acid‐dependent negative photochromism. The unusual photochromic behavior can be understood by direct protonation on the photoactive π‐system due to the unique electronic structure of azulene.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Defects at the bulk grain boundaries and heterojunction interfaces could dictate the power losses of perovskite solar cells (PSCs) during the operation process, which are regarded as major roadblocks ...towards further development of this emerging photovoltaic technology. The common modulation strategies reported for the state-of-the-art cells cannot concurrently heal the defects located at the grain boundaries and interfaces. Herein, a depth-dependent manipulation strategy is demonstrated to concurrently modulate the bulk and interfacial defects in the perovskite films. According to the distinct penetrability of the employed binary modulators within the polycrystalline perovskite film, one of the modulators can penetrate through the bulk to the buried interface, accompanied by bulk and buried interface defect healing, while the other remains to anchor atop the surface along with the surface defect modulation, assuring simultaneous defect management from the interfaces to the bulk. As a result, the mitigated non-radiative losses and the improved charge transport of the modulated perovskite film boost the efficiency of PSCs from 21.79% to 24.36%. This universally effective depth-dependent manipulation strategy provides new insights into spatial defect modulation, which would open up a promising way for defect modulator design for highly efficient perovskite optoelectronic devices.
The depth-dependent defect manipulation strategy using binary modulators with selective penetrability within perovskite films can concurrently passivate the defects both in bulk and at interfaces, boosting the efficiency of the solar cell to 24.36%.
Perovskite nanocrystals are exceptional candidates for light-emitting diodes (LEDs). However, they are unstable in the solid film and tend to degrade back to the bulk phase, which undermines their ...potential for LEDs. Here we demonstrate that perovskite nanocrystals stabilized in metal–organic framework (MOF) thin films make bright and stable LEDs. The perovskite nanocrystals in MOF thin films can maintain the photoluminescence and electroluminescence against continuous ultraviolet irradiation, heat and electrical stress. As revealed by optical and X-ray spectroscopy, the strong emission originates from localized carrier recombination. Bright LEDs made from perovskite-MOF nanocrystals are demonstrated with a maximum external quantum efficiency of over 15% and a high brightness of over 105 cd m−2 after the device reaches stabilization. During LED operation, the nanocrystals can be well preserved, free of ion migration or crystal merging through protection by the MOF matrix, leading to a stable performance over 50 hours.The use of metal–organic frameworks helps protect perovskite nanocrystals, resulting in bright, stable light-emitting diodes.
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GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Synthesis of two dicyclopentaannelated hexa‐peri‐hexabenzocoronene (PHBC) regioisomers was carried out, using nonplanar oligoaryl precursors with fluorenyl groups: mPHBC 8 with two pentagons in the ...“meta”‐configuration was obtained as a stable molecule, while its structural isomer with the “para”‐configuration, pPHBC 16, could be generated and characterized only in situ due to its high chemical reactivity. Both PHBCs exhibit low energy gaps, as reflected by UV‐vis‐NIR absorption and electrochemical measurements. They also show open‐shell singlet ground states according to electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations. The use of fully benzenoid HBC as a bridging moiety leads to significant singlet biradical characters (y0) of 0.72 and 0.96 for mPHBC 8 and pPHBC 16, respectively, due to the strong rearomatization tendency of the HBC π‐system; these values are among the highest for planar carbon‐centered biradical molecules. The incorporation of fully unsaturated pentagons strongly perturbs the aromaticity of the parent HBC and makes the constituted benzene rings less aromatic or antiaromatic. These results illustrate the high impact of cyclopentaannelation on the electronic structures of fully benzenoid polycyclic aromatic hydrocarbons (PAHs) and open up a new avenue towards open‐shell PAHs with prominent singlet biradical characters.
Incorporation of two fully unsaturated pentagons to the bay positions of hexa‐peri‐hexabenzocoronene (HBC) core gives access to two dicyclopentaannelated HBC regioisomers: mPHBC and pPHBC. Both compounds show decreased energy gaps compared with the parent HBC and exhibit singlet biradical ground state with prominent biradical character.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Unsupervised domain adaptation deals with scenarios in which labeled data are available in the source domain, but only unlabeled data can be observed in the target domain. Since the classifiers ...trained by source-domain data would not be expected to generalize well in the target domain, how to transfer the label information from source to target-domain data is a challenging task. A common technique for unsupervised domain adaptation is to match cross-domain data distributions, so that the domain and distribution differences can be suppressed. In this paper, we propose to utilize the label information inferred from the source domain, while the structural information of the unlabeled target-domain data will be jointly exploited for adaptation purposes. Our proposed model not only reduces the distribution mismatch between domains, improved recognition of target-domain data can be achieved simultaneously. In the experiments, we will show that our approach performs favorably against the state-of-the-art unsupervised domain adaptation methods on benchmark data sets. We will also provide convergence, sensitivity, and robustness analysis, which support the use of our model for cross-domain classification.
Behçet's disease (BD) can involve any site of the alimentary canal. There has been research concerning intestinal BD. Nevertheless, the entire digestive tract not yet been studied extensively. ...Therefore, the purpose of study was to describe the prevalence, location, clinical features and possible risk factors of BD with gastrointestinal tract ulcer. This was a cross-sectional observational study that included 1232 consecutive BD patients who routinely underwent endoscopy upon their wishes. The clinical symptoms, endoscopic findings, and histologic features of BD with gastrointestinal ulcer and negative Helicobacter pylori (Hp) were identified. We found that 22.16% (273/1232) BD patients had ulcers of the alimentary tract. At presentation, 61.54% (168/273) patients were asymptomatic. Isolated gastroduodenal involvement is an extremely usual event. The second was the pairwise combination between bowel segments, and 24 cases involved three segments at the same time. One patient suffered from total gastrointestinal tract involvement. Inflammation was the most common histopathologic feature 77.60% (142/183). The 273 BD patients with gastrointestinal ulcer were at greater risk of having archenteric symptoms (OR 0.070, P < 0.001), fever (OR 0.115, P = 0.047), high CRP (OR 0.994, P = 0.027) and BDCAF level (OR 0.590, P = 0.010). Uveitis correlates negatively with gastrointestinal involvement in BD patients (OR 3.738, P = 0.011). BD could affect the upper gastrointestinal tract independently. Endoscopy should be conducted in all patients in whom a diagnosis of BD is entertained, especially in patients with higher CRP, disease activity and fever. While, BD patients with uveitis correlates negatively with gastrointestinal involvement.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Inflammatory signals from immunological cells may cause damage to intestinal epithelial cells (IECs), resulting in intestinal inflammation and tissue impairment. Interferon‐γ‐inducible protein 16 ...(IFI16) was reported to be involved in the pathogenesis of Behçet's syndrome (BS). This study aimed to investigate how inflammatory cytokines released by immunological cells and IFI16 participate in the pathogenesis of intestinal BS. RNA sequencing and real‐time quantitative PCR (qPCR) showed that the positive regulation of tumor necrosis factor‐α (TNF‐α) production in peripheral blood mononuclear cells (PBMCs) of intestinal BS patients may be related to the upregulation of polo like kinase 1 (PLK1) in PBMCs (P = 0.012). The plasma TNF‐α protein level in intestinal BS was significantly higher than in healthy controls (HCs; P = 0.009). PBMCs of intestinal BS patients and HCs were co‐cultured with human normal IECs (NCM460) to explore the interaction between immunological cells and IECs. Using IFI16 knockdown, PBMC‐NCM460 co‐culture, TNF‐α neutralizing monoclonal antibody (mAb), stimulator of interferon genes (STING) agonist 2′3′‐cGAMP, and the PLK1 inhibitor SBE 13 HCL, we found that PLK1 promotes the secretion of TNF‐α from PBMCs of intestinal BS patients, which causes overexpression of IFI16 and induces apoptosis of IECs via the STING–TBK1 pathway. The expressions of IFI16, TNF‐α, cleaved caspase 3, phosphorylated STING (pSTING) and phosphorylated tank binding kinase 1 (pTBK1) in the intestinal ulcer tissue of BS patients were significantly higher than that of HCs (all P < 0.05). PLK1 in PBMCs of intestinal BS patients increased TNF‐α secretion, inducing IEC apoptosis via activation of the IFI16–STING–TBK1 pathway. PLK1 and the IFI16–STING–TBK1 pathway may be new therapeutic targets for intestinal BS.
Model summarizing interactions between peripheral blood mononuclear cells (PBMCs) of intestinal Behçet's syndrome (BS) and intestinal epithelial cells (IECs). High expression of polo like kinase 1 (PLK1) promoted tumor necrosis factor‐α (TNF‐α) production and secretion from intestinal BS PBMCs that furthers the increase of interferon‐γ‐inducible protein 16 (IFI16) in IECs. IFI16 then induces IEC apoptosis via activation of the STING–TBK1 pathway.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Most chemical vapor deposition methods for transition metal dichalcogenides use an extremely small amount of precursor to render large single-crystal flakes, which usually causes low ...coverage of the materials on the substrate. In this study, a self-capping vapor-liquid-solid reaction is proposed to fabricate large-grain, continuous MoS
2
films. An intermediate liquid phase-Na
2
Mo
2
O
7
is formed through a eutectic reaction of MoO
3
and NaF, followed by being sulfurized into MoS
2
. The as-formed MoS
2
seeds function as a capping layer that reduces the nucleation density and promotes lateral growth. By tuning the driving force of the reaction, large mono/bilayer (1.1 mm/200 μm) flakes or full-coverage films (with a record-high average grain size of 450 μm) can be grown on centimeter-scale substrates. The field-effect transistors fabricated from the full-coverage films show high mobility (33 and 49 cm
2
V
−1
s
−1
for the mono and bilayer regions) and on/off ratio (1 ~ 5 × 10
8
) across a 1.5 cm × 1.5 cm region.
Neuromorphic electronics, being inspired by how the brain works, hold great promise to the successful implementation of smart artificial systems. Among several neuromorphic hardware issues, a robust ...device functionality under extreme temperature is of particular importance for practical applications. Given that the organic memristors for artificial synapse applications are demonstrated under room temperature, achieving a robust device performance at extremely low or high temperature is still utterly challenging. In this work, the temperature issue is addressed by tuning the functionality of the solution‐based organic polymeric memristor. The optimized memristor demonstrates a reliable performance under both the cryogenic and high‐temperature environments. The unencapsulated organic polymeric memristor shows a robust memristive response under test temperature ranging from 77 to 573 K. Utilizing X‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary‐ion mass spectrometry (ToF‐SIMS) depth profiling, the device working mechanism is unveiled by comparing the compositional profiles of the fresh and written organic polymeric memristors. A reversible ion migration induced by an applied voltage contributes to the characteristic switching behavior of the memristor. Herein, both the robust memristive response achieved at extreme temperatures and the verified device working mechanism will remarkably accelerate the development of memristors in neuromorphic systems.
An organic polymeric memristive device using MDMO‐PPV is demonstrated. The unencapsulated devices maintain reliable memristive switching behavior under an ultra‐wide temperature range (77–573 K). XPS and ToF‐SIMS depth profiling techniques are utilized to visualize the kinetic process of ion migration in the device. This work may allow the use of organic memristors as robust artificial synapses in ultra‐wide temperature range for future neuromorphic applications.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A large number of highly active Ru‐based electrocatalysts have been reported for the hydrogen evolution reaction (HER). The utilization of synergistic effects for promoting HER performance remains ...inadequate, especially for corresponding potential‐driven reactive sites at the atomic level. Herein, a Co‐substituted RuRu2P structure is employed as a model system to reveal the synergistic effect on Ru‐based electrocatalysts and to realize the potential‐driven reactive sites during the HER. Optimized RuRu2P @ Co0.6 exhibits a superior catalytic performance in alkaline electrolytes, achieving a low overpotential of 9 mV at a current density of 10 mA cm–2. To precisely describe the geometrical nature of surface moiety of Co(µ‐O)2Ru, an indicator (β) is established to quantify the strain of Co(µ‐O)2Ru moieties through calculating the LCoL (L = P or O) angles through employing in situ X‐ray absorption spectroscopy. Both bond strain and corresponding metal‐metal distance of CoRu in Co(µ‐O)2Ru moiety can significantly affect the structural tolerance and facilitate the coupling of adsorbed hydrogen atoms during HER. It is believed that the perspective raised in the present work will provide a new avenue to the design of highly active HER catalysts at the atomic scale.
An indicator (β) is established to quantify the strain of Co(μ‐O)2Ru moieties by calculating the LCoL (L = P or O) angles by employing in situ X‐ray absorption spectroscopy. The bond strain of CoRu in Co(μ‐O)2Ru moiety can significantly affect the structural tolerance and facilitate the coupling of adsorbed hydrogen atoms during the hydrogen evolution reaction.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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