Recently, sensors that can imitate human skin have received extensive attention. Capacitive sensors have a simple structure, low loss, no temperature drift, and other excellent properties, and can be ...applied in the fields of robotics, human–machine interactions, medical care, and health monitoring. Polymer matrices are commonly employed in flexible capacitive sensors because of their high flexibility. However, their volume is almost unchanged when pressure is applied, and they are inherently viscoelastic. These shortcomings severely lead to high hysteresis and limit the improvement in sensitivity. Therefore, considerable efforts have been applied to improve the sensing performance by designing different microstructures of materials. Herein, two types of sensors based on the applied forces are discussed, including pressure sensors and strain sensors. Currently, five types of microstructures are commonly used in pressure sensors, while four are used in strain sensors. The advantages, disadvantages, and practical values of the different structures are systematically elaborated. Finally, future perspectives of microstructures for capacitive sensors are discussed, with the aim of providing a guide for designing advanced flexible and stretchable capacitive sensors via ingenious human‐made microstructures.
The advantages, disadvantages, and practical applications of several popular microstructures that are widely employed in capacitive sensors are summarized. A microstructured dielectric layer or electrode can improve sensor sensitivity, reduce hysteresis, and endow the rigid electronic device with excellent elastic stretchability, which is an essential part of next‐generation wearable devices and soft robots.
Chemodynamic therapy (CDT) is a new emerging strategy for the in situ treatment of tumors. In the microenvironment of tumor cells, CDT may be achieved through the generation of reactive oxygen ...species (ROS), e.g., hydroxyl radicals (˙OH) and singlet oxygen (
O
), which induce the death of tumor cells. Copper (Cu) or other transition-metal ions catalyze the production of ˙OH by hydrogen peroxide (H
O
) through Fenton or Fenton-like reactions. With the development of advanced nanotechnology, nanotherapeutic systems with Cu-based nanostructures have received extensive attention and have been demonstrated for their wide applications in the design and construction of nanotherapeutic systems for CDT, along with multimodal synergistic therapy. Herein, the cutting-edge developments of Cu-based nanostructures in CDT are reviewed and discussed, by focusing on the monotherapy of CDT as well as synergistic treatments by hyphenating CDT with various therapeutic protocols, e.g., photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), and so on. In addition, the potential challenges and future perspectives are described in the improvement of CDT therapeutic efficacy, the enhancement of targeting capability, and mechanistic investigations on CDT therapy.
Artemisinin is a type of sesquiterpene lactone well known as an antimalarial drug, and is specifically produced in glandular trichomes of Artemisia annua. However, the regulatory network for the ...artemisinin biosynthetic pathway remains poorly understood. Exploration of trichome-specific transcription factors would facilitate the elucidation of regulatory mechanism of artemisinin biosynthesis.
The WRKY transcription factor GLANDULAR TRICHOME-SPECIFIC WRKY 1 (AaGSW1) was cloned and analysed in A. annua. AaGSW1 exhibited similar expression patterns to the trichome-specific genes of the artemisinin biosynthetic pathway and AP2/ERF transcription factor AaORA. A β-glucuronidase (GUS) staining assay further demonstrated that AaGSW1 is a glandular trichome-specific transcription factor.
AaGSW1 positively regulates CYP71AV1 and AaORA expression by directly binding to the W-box motifs in their promoters. Overexpression of AaGSW1 in A. annua significantly improves artemisinin and dihydroartemisinic acid contents; moreover, AaGSW1 can be directly regulated by AaMYC2 and AabZIP1, which are positive regulators of jasmonate (JA)-and abscisic acid (ABA)-mediated artemisinin biosynthetic pathways, respectively.
These results demonstrate that AaGSW1 is a glandular trichome-specific WRKY transcription factor and a positive regulator in the artemisinin biosynthetic pathway. Moreover, we propose that two trifurcate feed-forward pathways involving AaGSW1, CYP71AV1 and AaMYC2/AabZIP1 function in the JA/ABA response in A. annua.
Three regioregular benzodithiophene‐based donor–donor (D–D)‐type polymers (PBDTT, PBDTT1Cl, and PBDTT2Cl) are designed, synthesized, and used as donor materials in organic solar cells (OSCs). Because ...of the weak intramolecular charge‐transfer effect, these polymers exhibit large optical bandgaps (>2.0 eV). Among these three polymers, PBDTT1Cl exhibits more ordered and closer molecular stacking, and its devices demonstrate higher and more balanced charge mobilities and a longer charge‐separated state lifetime. As a result of these comprehensive benefits, PBDTT1Cl‐based OSCs give a very impressive power conversion efficiency (PCE) of 17.10% with a low nonradiative energy loss (0.19 eV). Moreover, PBDTT1Cl also possesses a low figure‐of‐merit value and good universality to match with different acceptors. This work provides a simply and efficient strategy to design low‐cost high‐performance polymer donor materials.
Three D–D type wide‐bandgap donor polymers (PBDTT, PBDTT1Cl, and PBDTT2Cl) are designed and facilely synthesized. Organic solar cells (OSCs) based on PBDTT1Cl exhibit a high power conversion efficiency of 17% and a low nonradiative energy loss of 0.19 eV. In addition, PBDTT1Cl has a very low figure‐of‐merit and good universality, indicating its potential as a low‐cost polymer donor for high‐performance OSCs.
Exploiting useful contacts: The exceptional catalytic performance of a photocatalyst composed of Pd nanoparticles and mesoporous carbon nitride for the dehydrogenation of formic acid in water at room ...temperature to produce H2 gas (see picture) is due to enhanced electron enrichment of the Pd nanoparticles through charge transfer at the interface of the Mott–Schottky contact.
Glandular trichomes are generally considered biofactories that produce valuable chemicals. Increasing glandular trichome density is a very suitable way to improve the productivity of these valuable ...metabolites, but little is known about the regulation of glandular trichome formation. Phytohormone jasmonate (JA) promotes glandular trichome initiation in various plants, but its mechanism is also unknown.
By searching transcription factors regulated by JA in Artemisia annua, we identified a novel homeodomain-leucine zipper transcription factor, HOMEODOMAIN PROTEIN 1 (AaHD1), which positively controls both glandular and nonglandular trichome initiations. Overexpression of AaHD1 in A. annua significantly increased glandular trichome density without harming plant growth. Consequently, the artemisinin content was improved.
AaHD1 interacts with A. annua jasmonate ZIM-domain 8 (AaJAZ8), which is a repressor of JA, thereby resulting in decreased transcriptional activity. AaHD1 knockdown lines show decreased sensitivity to JA on glandular trichome initiation, which indicates that AaHD1 plays an important role in JA-mediated glandular trichome initiation.
We identified a new transcription factor that promotes A. annua glandular trichome initiation and revealed a novel molecular mechanism by which a homeodomain protein transduces JA signal to promote glandular trichome initiation. Our results also suggested a connection between glandular and nonglandular trichome formations.
Elevation in homocysteine (Hcy) level is associated with insulin resistance; however, the causality between them and the underlying mechanism remain elusive. Here, we show that Hcy induces insulin ...resistance and causes diabetic phenotypes by protein cysteine-homocysteinylation (C-Hcy) of the pro-insulin receptor (pro-IR). Mechanistically, Hcy reacts and modifies cysteine-825 of pro-IR in the endoplasmic reticulum (ER) and abrogates the formation of the original disulfide bond. C-Hcy impairs the interaction between pro-IR and the Furin protease in the Golgi apparatus, thereby hindering the cleavage of pro-IR. In mice, an increase in Hcy level decreases the mature IR level in various tissues, thereby inducing insulin resistance and the type 2 diabetes phenotype. Furthermore, inhibition of C-Hcy in vivo and in vitro by overexpressing protein disulfide isomerase rescues the Hcy-induced phenotypes. In conclusion, C-Hcy in the ER can serve as a potential pharmacological target for developing drugs to prevent insulin resistance and increase insulin sensitivity.
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•Increased levels of Hcy decrease the abundance of IR-α and IR-β•Hcy reacts with pro-IR through its thiol group and thus regulates pro-IR cleavage•Furin plays an important role in cleavage of pro-IR into its mature/active forms•Inhibition of cysteine- homocysteinylation refreshes the insulin signal
Zhang et al. show that homocysteine (Hcy) induces insulin resistance and causes diabetic phenotypes by protein cysteine-homocysteinylation of the pro-insulin receptor. The findings suggest that cysteine-homocysteinylation in the endoplasmic reticulum could be an ideal therapeutic target to prevent insulin resistance.
Three nonfused ring electron acceptors (NFREAs), namely, 3TT‐C2‐F, 3TT‐C2‐Cl, and 3TT‐C2, are purposefully designed and synthesized with the concept of halogenation. The incorporation of F or/and Cl ...atoms into the molecular structure (3TT‐C2‐F and 3TT‐C2‐Cl) enhances the π–π stacking, improves electron mobility, and regulates the nanofiber morphology of blend films, thus facilitating the exciton dissociation and charge transport. In particular, blend films based on D18:3TT‐C2‐F demonstrate a high charge mobility, an extended exciton diffusion distance, and a well‐formed nanofiber network. These factors contribute to devices with a remarkable power conversion efficiency of 17.19%, surpassing that of 3TT‐C2‐Cl (16.17%) and 3TT‐C2 (15.42%). To the best of knowledge, this represents the highest efficiency achieved in NFREA‐based devices up to now. These results highlight the potential of halogenation in NFREAs as a promising approach to enhance the performance of organic solar cells.
Three nonfused ring electron acceptors (3TT‐C2‐F, 3TT‐C2‐Cl, and 3TT‐C2) are designed and synthesized with the concept of halogenation. Among them, the fluorinated acceptor 3TT‐C2‐F based devices can deliver the champion power conversion efficiency of over 17% due to enhanced the π–π stacking, improved the electron mobility, etc.
Crop diversity management is widely used to increase agricultural productivity and sustainability. Recent studies have demonstrated that maize root exudates can drive interspecific facilitation to ...enhance N2 fixation of bean in intercropping systems. However, the mechanisms of N2 fixation enhancement stimulated by root exudates in the intercropping systems remain unclear.
Four experiments were designed to provide a progressively deeper understanding of how root exudates stimulate microbial‐mediated N2 fixation. First, the effects of faba bean/maize intercropping on yields and soil microbial communities were determined in a field experiment. Second, root‐derived interspecific facilitation was evaluated using a root partitioning approach. Third, the key microbial taxa in the faba bean rhizosphere were traced using 13C‐labelled maize root exudates. Fourth, the co‐driven mechanism of maize root exudates and micro‐organisms in the faba bean rhizosphere were explored.
Faba bean/maize intercropping with maize residue return increased the yields of faba bean (26%), maize (27%) and broccoli (9.1%) compared to that under monocropping. Nodulin‐like 4 (NODL4), chalcone‐flavanone isomerase (CFI) and early nodulin‐like (ENODL2) gene expression in faba bean roots intercropped with maize increased by 1.5–2.3‐fold compared to that observed under monoculture. More than half of the N2 fixation of faba bean increase under intercropping was due to interactions with micro‐organisms. Nine key bacterial genera in the faba bean rhizosphere were identified by 13C‐DNA‐based stable isotope probing analysis. Among them Agromyces, Arthrobacter, Bacillus, Lysobacter and Paenibacillus directly fix N2, while Gemmatimonas, Heliobacillus, Natronocella and Sorangium increase the N2 fixation capacity of Azotobacter by providing additional carbon sources. These key bacteria triggered by maize root exudates played an important role in the rhizosphere facilitation of intercropping.
Synthesis and applications. We demonstrated a novel root–root facilitation of N2 fixation and increased crop yields co‐driven by root exudates and rhizosphere bacteria under faba bean/maize intercropping, and nine key bacteria associated with this process were identified by 13C‐DNA‐based stable isotope probing. We recommend the adoption and optimization of intercropping systems with residue return to reduce the shortcomings of continuous cropping and to increase the sustainability of crop production.
摘要
作物多样性管理被广泛用于提高农业生产力与可持续性。最近的研究表明, 玉米根系分泌物可以促进种间互惠作用, 从而提高间作系统中豆科作物的固氮能力。然而, 套作系统中根系分泌物引起的豆科作物固氮量增加的机制尚不清楚。
我们设计了四个逐步加深试验来研究根系分泌物如何富集微生物并提高豆科作物固氮能力的机制。首先, 通过田间试验确定了蚕豆/玉米间作对作物产量和土壤微生物群落的影响。其次, 采用根系隔离方法验证根际种间互惠作用是否存在。利用13C标记的玉米根系分泌物对蚕豆根际关键微生物类群进行了示踪。第四, 探讨了玉米根系分泌物和蚕豆根际微生物对种间互惠作用的协同驱动机制。
蚕豆/玉米间作结合玉米秸秆还田蚕豆、玉米和西兰花分别比对应单作增产26%、27%和9.1%。玉米间作蚕豆根部关键结瘤基因NODL4、ENODL2和查尔酮‐黄酮异构酶CFI的表达量比单作增加1.5 ~ 2.3倍。间作条件下, 蚕豆固氮量增加的一半以上来源于微生物的作用。采用13C‐DNA稳定同位素探针方法, 鉴定出了9个利用玉米根系分泌物的蚕豆根际关键细菌。其中Agromyces、Arthrobacter、Bacillus、Lysobacter和Paenibacillus直接固氮, 而Gemmatimonas、Heliobacillus、Natronocella和Sorangium则通过提供额外的碳源增加固氮菌的固氮能力。这些由玉米根系分泌物招集的关键细菌在间作根际互惠效应中起着重要作用。
理论与应用。我们揭示了蚕豆/玉米间作根系分泌物和根际微生物细菌共同驱动的根系固氮促进和作物产量增加的新机制, 并通过13C‐DNA‐稳定同位素探针鉴定出与此过程密切相关的9种关键细菌。建议采用并优化间作模式, 结合秸秆还田技术, 以减少连作障碍, 提高粮食生产的可持续性。
We demonstrated a novel root–root facilitation of N2 fixation and increased crop yields co‐driven by root exudates and rhizosphere bacteria under faba bean/maize intercropping, and nine key bacteria associated with this process were identified by 13C‐DNA‐based stable isotope probing. We recommend the adoption and optimization of intercropping systems with residue return to reduce the shortcomings of continuous cropping and to increase the sustainability of crop production.
Concentrated leachate from membrane treatment process, which contains large amount of difficult-to-degrade humic substances, can induce potential hazards to ecological environment. In this study, the ...concentrated leachates from reverse osmosis (RO) and nanofiltration (NF) were treated by continuous ozone generating-reaction integrated equipment, and the removal characteristics of humic substances were analyzed using gel filtration chromatography (GFC), excitation-emission matrix fluorescence spectroscopy (EEM), XAD-8 resin fractionation, and Fourier transform infrared spectroscopy (FTIR). The results of XRD-8 fractionation and SUVA254 showed that the humic substances including humic acid (HA) and fulvic acid (FA), were effectively removed along with the breakdown of aromatic hydrocarbons and decrease in the degree of humification during the ozonation process. After 110min of reaction, HA in both concentrated leachates was completely removed. GFC analysis indicated that both concentrated leachates had much broader distribution after the degradation. The high molecular weight (MW) organic matter was transformed into low molecular weight of <10kDa. The majority of high MW organics in NF concentrate were converted to low MW molecules of 10kDa-1kDa, while those in RO concentrate were decomposed to small MW molecules of <1kDa. The results of EEM analysis implied that the degradation of HA and FA led to a significant decrease in the fluorescence intensity. Though the effluent of two concentrated leachate did not meet the maximum allowable criterion for leachate direct or indirect discharge standard in China, the composition and properties of organic matters in concentrated leachate were changed significantly after entire ozonation reaction, which would be conducive to the further biological treatment or other advanced treatment.
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