Grain size is an important component trait of grain yield, which is frequently threatened by abiotic stress. However, little is known about how grain yield and abiotic stress tolerance are regulated. ...Here, we characterize GSA1, a quantitative trait locus (QTL) regulating grain size and abiotic stress tolerance associated with metabolic flux redirection. GSA1 encodes a UDP-glucosyltransferase, which exhibits glucosyltransferase activity toward flavonoids and monolignols. GSA1 regulates grain size by modulating cell proliferation and expansion, which are regulated by flavonoid-mediated auxin levels and related gene expression. GSA1 is required for the redirection of metabolic flux from lignin biosynthesis to flavonoid biosynthesis under abiotic stress and the accumulation of flavonoid glycosides, which protect rice against abiotic stress. GSA1 overexpression results in larger grains and enhanced abiotic stress tolerance. Our findings provide insights into the regulation of grain size and abiotic stress tolerance associated with metabolic flux redirection and a potential means to improve crops.
Despite the recent unprecedented development of efficient dopant‐free hole transporting materials (HTMs) for high‐performance perovskite solar cells (PSCs) on small‐area devices (≤0.1 cm2), low‐cost ...dopant‐free HTMs for large‐area PSCs (≥1 cm2) with high power conversion efficiencies (PCEs) have rarely been reported. Herein, two novel HTMs, 3,3′,6,6′ (or 2,2′,7,7′)‐tetrakis(N,N′‐di‐p‐methoxyphenylamine)‐N,N′‐bicarbazole (3,6 BCz‐OMeTAD or 2,7 BCz‐OMeTAD), are synthesized via an extremely simple route from very cheap raw materials. Owing to their excellent film‐forming abilities and matching energy levels, 3,6 BCz‐OMeTAD and 2,7 BCz‐OMeTAD can be successfully employed as a perfect ultrathin (≈30 nm) hole transporting layer in large‐area PSCs up to 1 cm2. The 3,6 BCz‐OMeTAD and 2,7 BCz‐OMeTAD based large‐area PSCs show highest PCEs up to 17.0% and 17.6%, respectively. More importantly, high performance large‐area PSCs based on 2,7 BCz‐OMeTAD retain 90% of the initial efficiency after 2000 h storage in an ambient environment without encapsulation.
Two novel low‐cost N,N′‐bicarbazole‐based hole‐transporting material (HTMs), 3,6 BCz‐OMeTAD and 2,7 BCz‐OMeTAD, are developed as efficient dopant‐free HTMs for large‐area perovskite solar cells (PSCs). 1 cm2 large‐area PSCs using ultrathin, dopant‐free 3,6 BCz‐OMeTAD and 2,7 BCz‐OMeTAD as hole‐transporting layers exhibit excellent power conversion efficiencies up to 17.0% and 17.6%, respectively.
Sepsis is life-threatening and often leads to acute brain damage. Dexmedetomidine, an α
-adrenoceptor agonist, has been reported to possess neuroprotective effects against various brain injury but ...underlying mechanisms remain elusive. In this study, in vitro and in vivo models of sepsis were used to explore the effects of dexmedetomidine on the inflammasome activity and its associated glia pyroptosis and neuronal death. In vitro, inflammasome activation and pyroptosis were found in astrocytes following lipopolysaccharide (LPS) exposure. Dexmedetomidine significantly alleviated astrocyte pyroptosis and inhibited histone release induced by LPS. In vivo, LPS treatment in rats promoted caspase-1 immunoreactivity in astrocytes and caused an increase in the release of pro-inflammatory cytokines of IL-1β and IL-18, resulting in neuronal injury, which was attenuated by dexmedetomidine; this neuroprotective effect was abolished by α
-adrenoceptor antagonist atipamezole. Dexmedetomidine significantly reduced the high mortality rate caused by LPS challenge. Our data demonstrated that dexmedetomidine may protect glia cells via reducing pyroptosis and subsequently protect neurons, all of which may preserve brain function and ultimately improve the outcome in sepsis.
In mammals, cytosolic sensors retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) activate multiple signaling cascades initiating IFN-α/β expression. IFN regulatory factor 3 (IRF3) is ...required for the activation of IFN-β, which, in turn, primes the expression of most IFN-α genes by IFN-induced IRF7 through the STAT1 pathway. In fish, RIG-I overexpression inhibits virus infection by induction of IFN response; however, the subtle signaling cascade mechanism remains to be identified. In this study, we clone an ortholog of MITA, a recently identified adaptor responsible for RLR pathway, from crucian carp (Carassius auratus L.), and demonstrate its ability to suppress viral replication through IRF3/7-dependent IFN response. The pivotal signaling molecules of RLR pathway, including RIG-I, melanoma differentiation-associated gene 5, laboratory of genetics and physiology 2, and TANK-binding kinase 1, are also cloned and characterized, confirming that the RLR-mediated IFN activation is conserved from fish to mammals. Further characterization of distinct IFN gene activation reveals that zebrafish IFN1 and IFN3 are induced by the MITA pathway but are dependent on distinct transcription factors. Whereas fish IFN genes cannot be classified into IFN-α or IFN-β, zebrafish IFN1 is primarily regulated by IRF3, thereby resembling that of IFN-β, and zebrafish IFN3 is regulated by IRF7, thereby resembling of those of IFN-αs. In contrast with mammalian IFN-α/β, zebrafish IFN1 and IFN3 are induced by the basally expressed IRF3 or IRF7, both of which are upregulated by IFN and virus infection. Collectively, these data suggest that IFN genes in fish and mammals have evolved independently to acquire a similar mechanism triggering their expression.
Following transient forebrain ischemia, astrocytes play a key role in determining whether or not neurons in the hippocampal CA1 sector go on to die in a delayed fashion. MicroRNAs (miRNAs) are a ...novel class of RNAs that control gene expression at the post‐transcriptional level and the miR‐29 family is highly expressed in astrocytes. In this study we assessed levels of miR‐29 in hippocampus following forebrain ischemia and found that after transient forebrain ischemia and short periods of reperfusion, miR‐29a significantly increased in the resistant dentate gyrus, but decreased in the vulnerable CA1 region of the hippocampus. We demonstrate that miR‐29a targets BH3‐only proapoptotic BCL2 family member PUMA by luciferase reporter assay and by Western blot. Comparing primary neuron and astrocyte cultures, and postnatal brain, we verified the strongly astrocytic expression of miR‐29a. We further found that miR‐29a mimic protects and miR‐29a inhibitor aggravates cell injury and mitochondrial function after ischemia‐like stresses in vitro. Lastly, by overexpressing and reducing miR‐29a we demonstrate the protective effect of miR‐29a on CA1 delayed neuronal death after forebrain ischemia. Our data suggest that by targeting a pro‐apoptotic BCL2 family member, increasing levels of miR‐29a might emerge as a strategy for protection against ischemia‐reperfusion injury. GLIA 2013;61:1784–1794
When studying the vehicle routing problem, especially for on-time arrivals, the determination of travel time plays a decisive role in the optimization of logistics companies. Traffic Internet of ...Things (IoT) connects ubiquitous devices and collects data from various channels like traffic cameras, vehicle detectors, GPS, sensors, etc. that can be used to analyze real-time traffic status and eventually increase the efficiency of logistics management for Logistics 4.0. However, big IoT data contain joint features that interact non-linearly and complicatedly, thus increasing the stochastic nature and difficulty of determining travel time on real-time basis. This research proposes a novel method (named the gradient boosting partitioned regression tree model) to forecast travel time based on big data collected from the industrial IoT infrastructure. The proposed method separates the global regression tree model based on the gradient boosting decision tree into several partitions to capture the time-varying features simultaneously – that is, to subdivide the non-linearity into fragments and to characterize the feature interactions in a manageable way with recursive partitions. We illustrate several analytical properties with manageable advantages in terms of big data analytics of the proposed method and apply it to real traffic IoT data. Findings of this research show that the proposed method performs successfully at enhancing the predictive accuracy of travel time after empirically comparing it with other computational methods.
Chemical doping of organic semiconductors has been recognized as an effective way to enhance the electrical conductivity. In perovskite solar cells (PSCs), various types of dopants have been ...developed for organic hole transport materials (HTMs); however, the knowledge of the basic requirements for being efficient dopants as well as the comprehensive roles of the dopants in PSCs has not been clearly revealed. Here, three copper-based complexes with controlled redox activities are applied as dopants in PSCs, and it is found that the oxidative reactivity of dopants presents substantial impacts on conductivity, charge dynamics, and solar cell performance. A significant improvement of open-circuit voltage (V oc) by more than 100 mV and an increase of power conversion efficiency from 13.2 to 19.3% have been achieved by tuning the doping level of the HTM. The observed large variation of V oc for three dopants reveals their different recombination kinetics at the perovskite/HTM interfaces and suggests a model of an interfacial recombination mechanism. We also suggest that the dopants in HTMs can also affect the charge recombination kinetics as well as the solar cell performance. Based on these findings, a strategy is proposed to physically passivate the electron–hole recombination by inserting an ultrathin Al2O3 insulating layer between the perovskite and the HTM. This strategy contributes a significant enhancement of the power conversion efficiency and environmental stability, indicating that dopant engineering is one crucial way to further improve the performance of PSCs.
Graphene is an attractive optoelectronic material for light detection because of its broadband light absorption and fast response time. However, the relatively low absorption cross‐section, fast ...recombination rate, and the absence of gain mechanism have limited the responsivity of pure graphene‐based phototransistor to ≈10−2 A W−1. In this work, a photoconductive gain of ≈109 electrons per photon and a responsivity of ≈6.0 × 105 A W−1 are demonstrated in a hybrid photodetector that consists of monolayer graphene covered with a thin layer of dispersive organolead halide perovskite (CH3NH3PbBr2I) islands. The unprecedented performance is attributed to the effective charge transfer and photogating effect, which were evidenced by photoluminescence quenching, time‐resolved photoluminescence decay, scanning near‐field optical microscopy, and photocurrent mapping. Unlike previous report which used perovskite bulk thin film, the perovskite islands have low bulk recombination rate of photogenerated carriers. The device also shows broad photodetection spectral range from ultraviolet to visible (250–700 nm), affording new opportunities for scalable UV detectors and imaging sensors.
A photoconductive gain of ≈ 109 electrons per photon and a responsivity of ≈6.0 × 105 A W−1 are demonstrated in a hybrid photodetector that consists of monolayer graphene covered with a thin layer of dispersive organolead halide perovskite (CH3NH3PbBr2I) islands with sizes up to micrometers. The s‐scanning near‐field optical microscopy and photocurrent mapping results provide real‐space evidence for the charge transfer and photogating effect.
The present work investigated the binding of atomically dispersed transition metals to the perfect and single/double vacancy (SV/DV)‐containing defective β12‐borophenes and the catalytic performance ...of those corresponding single‐atom catalysts (SACs) and diatomic catalysts (DACs) for nitrogen reduction reaction (NRR) by means of density functional theory calculations. Although previous theoretical studies proposed that the inherent hexagon hole of the defect‐free β12‐borophene is capable of anchoring single metal atom for NRR, calculations suggested that the interaction between borophene and doped metal is not strong enough to avoid metal aggregation. For the defective β12‐borophene with SV, even though the single metal could be stabilized in an 8‐membered ring, it was found that the SAC was still ineffective for NRR because of the competitive hydrogen evolution process. Regarding the DV‐containing β12‐borophene, a defective configuration with an unexpected 11‐membered hole was proved as the most stable structure, which possessed a very similar average atomic energy (6.25 eV atom−1) compared to that of the pristine β12 sheet (6.26 eV atom−1). Two metal atoms could be encapsulated into the confined space of the B11 ring. Compared to SACs, those corresponding DACs were more active for N2 fixation and hydrogenation, and the hydrogen evolution reaction could be passivated, attributing to the synergistic effect of dual metal centres. Among all candidates, the V2/β12‐DV was predicted as the most promising catalyst for NRR, with the limiting potential of as low as −0.15 V.
Stable or not? This work discusses the strategy for metal dispersion on borophene and introduces a double vacancy‐containing β12‐sheet‐supported V2 diatomic catalyst, which promotes nitrogen electroreduction in a highly active and selective way.
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