Power and electronic components that are self‐healable, deformable, transparent, and self‐powered are highly desirable for next‐generation energy/electronic/robotic applications. Here, an ...energy‐harvesting triboelectric nanogenerator (TENG) that combines the above features is demonstrated, which can serve not only as a power source but also as self‐powered electronic skin. This is the first time that both of the triboelectric‐charged layer and electrode of the TENG are intrinsically and autonomously self‐healable at ambient conditions. Additionally, comparing with previous partially healable TENGs, its fast healing time (30 min, 100% efficiency at 900% strain), high transparency (88.6%), and inherent superstretchability (>900%) are much more favorable. It consists of a metal‐coordinated polymer as the triboelectrically charged layer and hydrogen‐bonded ionic gel as the electrode. Even after 500 cutting‐and‐healing cycles or under extreme 900%‐strain, the TENG retains its functionality. The generated electricity can be used directly or stored to power commercial electronics. The TENG is further used as self‐powered tactile‐sensing skin in diverse human–machine interfaces including smart glass, an epidermal controller, and phone panel. This TENG with merits including fast ambient‐condition self‐healing, high transparency, intrinsic stretchability, and energy‐extraction and actively‐sensing abilities, can meet wide application needs ranging from deformable/portable/transparent electronics, smart interfaces, to artificial skins.
The first entirely, intrinsically, and autonomously self‐healable, highly transparent, and superstretchable triboelectric nanogenerator is developed for not only energy sources but also self‐powered electronic skins. This unprecedented triboelectric nanogenerator with energy‐extracting and activity‐sensing abilities is timely and able to usher vast emerging fields including flexible/self‐powered electronics, smart interfaces, and prosthetic and robotic skins.
Searching an efficient and robust photocatalyst is important in converting solar energy into chemical energy for clean and renewable fuels. Thiophene and fluorene have been widely used in this field. ...However, no studies exist on understanding the effect of increasing the number of fused thiophene and fluorene rings. Herein, we demonstrated a series of polymer photocatalysts based on fused rings with fluorene (F) and indenofluorene (IF) units and fused-thiophene rings (thiophene (T), thienothiophene (2T), and dithienothiophene (3T)) in different combinations, denoted as PF
n
T and PIF
n
T, where
n
is the number of fused thiophene rings. We show that the increased number of fused rings on fluorene or thiophene units is important for photocatalytic performance. Particularly, without adding the noble Pt cocatalysts, our PF3T presented an excellent efficiency with a hydrogen evolution rate (HER) of 1095 µmol h
−1
g
−1
(
λ
> 420 nm). We show that the photocatalysts are robust, that is, PF2T could be used for over 70 hours. More importantly, even when we stored PF2T in a water/methanol/TEA solution for 20 days, its photocatalytic performance remained constant. This contribution documents the first systematic study on the construction of efficient and robust polymer photocatalysts, allowing the researcher to potentially target the number of fused rings on polymers and provides an important impact in this field.
The introduction of fused thiophene units into the fluorene analogues, for the first time, resulted in an improved photocatalytic performance of the polymer photocatalysts.
Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders. Its pathology is associated with the deposition of amyloid β (Aβ), an abnormal extracellular peptide. Moreover, its ...pathological progression is closely accompanied by neuroinflammation. Specifically, Aβ‐associated microglial overactivation may have the central role in AD pathogenesis. Interestingly, arginine metabolism may contribute to the equilibrium between M1 and M2 microglia. However, little is known about the involvement of arginine metabolism in Aβ‐induced microglial neuroinflammation and neurotoxicity. Moreover, the underlying mechanism by which Aβ induces the transition of microglia to the M1 phenotype remains unclear. In this study, we investigated the role of Aβ in mediating microglial activation and polarization both in vitro and in vivo. Our results demonstrated that under the Aβ treatment, ornithine decarboxylase (ODC), a rate‐limiting enzyme in the regulation of arginine catabolism, regulates microglial activation by altering the antizyme (AZ) + 1 ribosomal frameshift. Furthermore, the restoration of ODC protein expression levels has profound effects on inhibition of Aβ‐induced M1 markers and thus attenuates microglial‐mediated cytotoxicity. Altogether, our findings suggested that Aβ may contribute to M1‐like activation by disrupting the balance between ODC and AZ in microglia.
Our results revealed that ornithine decarboxylase (ODC) and polyamines may regulate M1 microglial activation via alterations in antizyme (AZ) + 1 ribosomal frameshifting during the amyloid β (Aβ) treatment. In addition, the restoration of ODC protein expression levels in BV2 microglia has profound effects on M1 phenotype inhibition and attenuates Aβ‐induced microglial‐mediated cytotoxicity.
By mimicking natural photosynthesis, generating hydrogen through visible-light-driven splitting of water would be an almost ideal process for converting abundant solar energy into a usable fuel in an ...environmentally friendly and high-energy-density manner. In a search for efficient photocatalysts that mimic such a function, here we describe a series of cycloplatinated polymer dots (Pdots), in which the platinum complex unit is presynthesized as a comonomer and then covalently linked to a conjugated polymer backbone through Suzuki–Miyaura cross-coupling polymerization. On the basis of our design strategy, the hydrogen evolution rate (HER) of the cycloplatinated Pdots can be enhanced by 12 times in comparison to that of pristine Pdots under otherwise identical conditions. In comparison to the Pt-complex-blended counterpart Pdots, the HER of cycloplatinated Pdots is over 2 times higher than that of physically blended Pdots. Furthermore, enhancement of the photocatalytic reaction time with high eventual hydrogen production and low efficiency rolloff are observed by utilizing the cycloplatinated Pdots as photocatalysts. On the basis of their performance, our cyclometallic Pdot systems appear to be alternative types of promising photocatalysts for visible-light-driven hydrogen evolution.
Conjugated polymers (CPs) have recently gained increasing attention as photocatalysts for sunlight-driven hydrogen evolution. However, they suffer from insufficient electron output sites and poor ...solubility in organic solvents, severely limiting their photocatalytic performance and applicability. Herein, solution-processable all-acceptor (A
-A
)-type CPs based on sulfide-oxidized ladder-type heteroarene are synthesized. A
-A
-type CPs showed upsurging efficiency improvements by two to three orders of magnitude, compared to their donor-acceptor -type CP counterparts. Furthermore, by seawater splitting, PBDTTTSOS exhibited an apparent quantum yield of 18.9% to 14.8% at 500 to 550 nm. More importantly, PBDTTTSOS achieved an excellent hydrogen evolution rate of 35.7 mmol h
g
and 150.7 mmol h
m
in the thin-film state, which is among the highest efficiencies in thin film polymer photocatalysts to date. This work provides a novel strategy for designing polymer photocatalysts with high efficiency and broad applicability.
Most cases of hepatocellular carcinoma (HCC) arise with the fibrotic microenvironment where hepatic stellate cells (HSCs) and carcinoma-associated fibroblasts (CAFs) are critical components in HCC ...progression. Therefore, CAF normalization could be a feasible therapy for HCC. Galectin-1 (Gal-1), a β-galactoside-binding lectin, is critical for HSC activation and liver fibrosis. However, few studies has evaluated the pathological role of Gal-1 in HCC stroma and its role in hepatic CAF is unclear. Here we showed that Gal-1 mainly expressed in HCC stroma, but not cancer cells. High expression of Gal-1 is correlated with CAF markers and poor prognoses of HCC patients. In co-culture systems, targeting Gal-1 in CAFs or HSCs, using small hairpin (sh)RNAs or an therapeutic inhibitor (LLS30), downregulated plasminogen activator inhibitor-2 (PAI-2) production which suppressed cancer stem-like cell properties and invasion ability of HCC in a paracrine manner. The Gal-1-targeting effect was mediated by increased a disintegrin and metalloprotease 17 (ADAM17)-dependent TNF-receptor 1 (TNFR1) shedding/cleavage which inhibited the TNF-α → JNK → c-Jun/ATF2 signaling axis of pro-inflammatory gene transcription. Silencing Gal-1 in CAFs inhibited CAF-augmented HCC progression and reprogrammed the CAF-mediated inflammatory responses in a co-injection xenograft model. Taken together, the findings uncover a crucial role of Gal-1 in CAFs that orchestrates an inflammatory CSC niche supporting HCC progression and demonstrate that targeting Gal-1 could be a potential therapy for fibrosis-related HCC.
Converting solar energy into hydrogen energy using conjugated polymers (CP) is a promising solution to the energy crisis. Improving water solubility plays one of the critical factors in enhancing the ...hydrogen evolution rate (HER) of CP photocatalysts. In this study, a novel concept of incorporating hydrophilic side chains to connect the backbones of CPs to improve their HER is proposed. This concept is realized through the polymerization of carbazole units bridged with octane, ethylene glycol, and penta‐(ethylene glycol) to form three new side‐chain‐braided (SCB) CPs: PCz2S‐OCt, PCz2S‐EG, and PCz2S‐PEG. Verified through transient absorption spectra, the enhanced capability of PCz2S‐PEG for ultrafast electron transfer and reduced recombination effects has been demonstrated. Small‐ and wide‐angle X‐ray scattering (SAXS/WAXS) analyses reveal that these three SCB‐CPs form cross‐linking networks with different mass fractal dimensions (f) in aqueous solution. With the lowest f value of 2.64 and improved water/polymer interfaces, PCz2S‐PEG demonstrates the best HER, reaching up to 126.9 µmol h−1 in pure water‐based photocatalytic solution. Moreover, PCz2S‐PEG exhibits comparable performance in seawater‐based photocatalytic solution under natural sunlight. In situ SAXS analysis further reveals nucleation‐dominated generation of hydrogen nanoclusters with a size of ≈1.5 nm in the HER of PCz2S‐PEG under light illumination.
Pioneer examples of side‐chain‐bridged polymer photocatalysts, of tunable hydrophilicity of the side chains are presented. These polymers are capable of generating hydrogen using natural sunlight in seawater‐based photocatalytic solution. The distinctive structural characteristics and impressive HER performance of the side‐chain‐bridged conjugated polymers suggest a potential avenue in the development of photocatalytic conjugated polymers.
Abstract Reactive oxygen species is the main contributor to photodynamic therapy. The results of this study show that a nitrogen-doped graphene quantum dot, serving as a photosensitizer, was capable ...of generating a higher amount of reactive oxygen species than a nitrogen-free graphene quantum dot in photodynamic therapy when photoexcited for only 3 min of 670 nm laser exposure (0.1 W cm-2 ), indicating highly improved antimicrobial effects. In addition, we found that higher nitrogen-bonding compositions of graphene quantum dots more efficiently performed photodynamic therapy actions than did the lower compositions that underwent identical treatments. Furthermore, the intrinsically emitted luminescence from nitrogen-doped graphene quantum dots and high photostability simultaneously enabled it to act as a promising contrast probe for tracking and localizing bacteria in biomedical imaging. Thus, the dual modality of nitrogen-doped graphene quantum dots presents possibilities for future clinical applications, and in particular multidrug resistant bacteria.
Abstract
Photocatalytic water splitting is attracting considerable interest because it enables the conversion of solar energy into hydrogen for use as a zero-emission fuel or chemical feedstock. ...Herein, we present a universal approach for inserting hydrophilic non-conjugated segments into the main-chain of conjugated polymers to produce a series of discontinuously conjugated polymer photocatalysts. Water can effectively be brought into the interior through these hydrophilic non-conjugated segments, resulting in effective water/polymer interfaces inside the bulk discontinuously conjugated polymers in both thin-film and solution. Discontinuously conjugated polymer with 10 mol% hexaethylene glycol-based hydrophilic segments achieves an apparent quantum yield of 17.82% under 460 nm monochromatic light irradiation in solution and a hydrogen evolution rate of 16.8 mmol m
−2
h
−1
in thin-film. Molecular dynamics simulations show a trend similar to that in experiments, corroborating that main-chain engineering increases the possibility of a water/polymer interaction. By introducing non-conjugated hydrophilic segments, the effective conjugation length is not altered, allowing discontinuously conjugated polymers to remain efficient photocatalysis.
