Management of the rice brown planthopper
Stål is challenging because it can rapidly adapt to new pesticides within several generations. Combined use of chemical insecticides and antimicrobials was ...proposed as an alternative strategy to control
. Our previous experiments identified two effective agents (chemical insecticide: pymetrozine and antimicrobial: zhongshengmycin) that act on different targets in
. However, conditions and effectiveness of combinations of antimicrobials and insecticides against
are still unknown. Here, we evaluated separate and combined effects of pymetrozine and zhongshengmycin on third instar nymphs of
under laboratory and greenhouse conditions. Results showed that zhongshengmycin exerts significant inhibitory effects on the three endosymbionts
,
, and
cultured
of
. Combinations of pymetrozine and zhongshengmycin under laboratory conditions produced additive or synergistic effects on
and caused higher mortality in third instar nymphs than either of them used alone. Experiments under greenhouse conditions further demonstrated that effective component quality ratio of pymetrozine to zhongshengmycin of 1:10 and 1:40 with co-toxicity coefficients of 221.63 and 672.87, respectively, also produced significant synergistic effects against
. Our results indicated that chemical insecticides combined with antimicrobials may provide a potential novel strategy for controlling
by inhibiting its endosymbionts.
Transcranial photobiomodulation (tPBM) has been suggested as a non-invasive neuromodulation tool. The repetitive administration of light-emitting diode (LED)-based tPBM for several weeks ...significantly improves human cognition. To understand the electrophysiological effects of LED-tPBM on the human brain, we investigated alterations by repeated tPBM in vigilance performance and brain networks using electroencephalography (EEG) in healthy participants. Active and sham LED-based tPBM were administered to the right forehead of young participants twice a week for four weeks. The participants performed a psychomotor vigilance task (PVT) during each tPBM/sham experiment. A 64-electrode EEG system recorded electrophysiological signals from each participant during the first and last visits in a 4-week study. Topographical maps of the EEG power enhanced by tPBM were statistically compared for the repeated tPBM effect. A new data processing framework combining the group's singular value decomposition (gSVD) with eLORETA was implemented to identify EEG brain networks. The reaction time of the PVT in the tPBM-treated group was significantly improved over four weeks compared to that in the sham group. We observed acute increases in EEG delta and alpha powers during a 10 min LED-tPBM while the participants performed the PVT task. We also found that the theta, beta, and gamma EEG powers significantly increased overall after four weeks of LED-tPBM. Combining gSVD with eLORETA enabled us to identify EEG brain networks and the corresponding network power changes by repeated 4-week tPBM. This study clearly demonstrated that a 4-week prefrontal LED-tPBM can neuromodulate several key EEG networks, implying a possible causal effect between modulated brain networks and improved psychomotor vigilance outcomes.
The CRISPR/Cas12a and CRISPR/Cas13d systems are widely used for fundamental research and hold great potential for future clinical applications. However, the short half-life of guide RNAs (gRNAs), ...particularly free gRNAs without Cas nuclease binding, limits their editing efficiency and durability.
Here, we engineer circular free gRNAs (cgRNAs) to increase their stability, and thus availability for Cas12a and Cas13d processing and loading, to boost editing. cgRNAs increases the efficiency of Cas12a-based transcription activators and genomic DNA cleavage by approximately 2.1- to 40.2-fold for single gene editing and 1.7- to 2.1-fold for multiplexed gene editing than their linear counterparts, without compromising specificity, across multiple sites and cell lines. Similarly, the RNA interference efficiency of Cas13d is increased by around 1.8-fold. In in vivo mouse liver, cgRNAs are more potent in activating gene expression and cleaving genomic DNA.
CgRNAs enable more efficient programmable DNA and RNA editing for Cas12a and Cas13d with broad applicability for fundamental research and gene therapy.
Poly(lactic acid) (PLA) electrospun membranes immobilized with Zeolitic imidazole framework/graphene oxide hybrid (ZIF-8@GO) are fabricated via electrospinning. At first, ZIF-8@GO is synthesized by ...the in situ growth method. The UV–visible light (UV–vis) result demonstrates that ZIF-8@GO has a narrower band gap than ZIF-8. The performance of the obtained composite membrane is investigated by scanning electron microscope, Fourier transform IR spectroscopy, tensile test, water contact angle, and methylene blue (MB) removal test. The results demonstrate that the degradable PLA/ZIF-8@GO electrospun membrane shows enhanced tensile strength than neat PLA. The composite membrane also shows great MB removal ability by adsorption and photocatalytic degradation. The MB removal efficiency could reach over 90% at very low ZIF-8@GO concentration (0.06 mg/mL).
Efficient removal of trace arsenites As(III) in groundwater is a big challenge worldwide. In this study, magnetic Fe3O4@poly(p-phenylenediamine)@TiO2 (Fe3O4@PpPDA@TiO2) core–shell nanoparticles ...were synthesized for As(III) ions removal via the photocatalytic oxidation–adsorption process. Under dark conditions, the As(III) adsorption on the as-synthesized core–shell nanoparticles obeyed the pseudo-second-order kinetic model and reached adsorption equilibrium within 45 min with a removal efficiency of 36.5%. Under visible-light irradiation, approximately 92% of As(III) ions were transformed into relatively low-toxic As(V) ions via the Fe3O4@PpPDA@TiO2 core–shell nanoparticles, and the arsenic removal efficiency increased dramatically to about 81% owing to As(V) ions being simultaneously adsorbed on the nanocomposite surfaces. The photocatalytic oxidation mechanisms were attributed to the synergism of photogenerated holes, hydroxyl radicals, and superoxide radicals. The as-synthesized Fe3O4@PpPDA@TiO2 core–shell nanoparticles are potentially useful in purifying the trace As(III)-contaminated groundwater owing to their easy magnetic separation, high optical quantum efficiency, and visible-light photocatalytic activity.
This paper studies the trajectory tracking control of a space robot system (SRS) in the presence of the lumped uncertainties with no prior knowledge of their upper bound. Although some related ...control methods have been proposed, most of them have either not been applied to SRSs or lack rigorous stability proof. Therefore, it is still a challenge to achieve high accuracy and rigorous theoretical proof for tracking control of SRSs. This paper proposes a new integrated neural network- based control scheme for the trajectory tracking of a SRS actuated by control moment gyros (CMGs). A new adaptive non-singular terminal sliding mode (ANTSM) control method is developed based on an improved radial basis function neural network (RBFNN). In the control method, a new weight update law is proposed to learn the upper bound of the lumped uncertainties. With the advantages of RBFNN and ANTSM, the controller has high control accuracy, fast learning speed and finite-time convergence. Different from most on-ground robotic manipulator controllers, a kinematic controller with position and attitude control laws is also designed for the satellite platform to remain stable. The stability of the closed-loop system is proved by the Lyapunov method with a high mathematical standard. Comparative simulation results demonstrate the effectiveness of the proposed control scheme with preferable performance and robustness.
Self-supervised learning aims to learn a universal feature representation without labels. To date, most existing self-supervised learning methods are designed and optimized for image classification. ...These pre-trained models can be sub-optimal for dense prediction tasks due to the discrepancy between image-level prediction and pixel-level prediction. To fill this gap, we aim to design an effective, dense self-supervised learning framework that directly works at the level of pixels (or local features) by taking into account the correspondence between local features. Specifically, we present dense contrastive learning (DenseCL), which implements self-supervised learning by optimizing a pairwise contrastive (dis)similarity loss at the pixel level between two views of input images. Compared to the supervised ImageNet pre-training and other self-supervised learning methods, our self-supervised DenseCL pre-training demonstrates consistently superior performance when transferring to downstream dense prediction tasks including object detection, semantic segmentation and instance segmentation. Specifically, our approach significantly outperforms the strong MoCo-v2 by 2.0% AP on PASCAL VOC object detection, 1.1% AP on COCO object detection, 0.9% AP on COCO instance segmentation, 3.0% mIoU on PASCAL VOC semantic segmentation and 1.8% mIoU on Cityscapes semantic segmentation. The improvements are up to 3.5% AP and 8.8% mIoU over MoCo-v2, and 6.1% AP and 6.1% mIoU over supervised counterpart with frozen-backbone evaluation protocol.
Code and models are available at: https://git.io/DenseCL
Self‐assembled monolayers (SAMs) have emerged as effective carrier transport layers in perovskite (PVK) solar cells because of their unique ability to manipulate interfacial property, as well as ...simple processing and scalable fabrication. However, the defects and pinholes derived from their sensitive adsorption process inevitably deteriorate the final device performance. Herein, a sputtered nickel oxide (NiOx) interlayer is used as a seed layer to promote the adsorption of the 2‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)ethylphosphonic acid (MeO‐2PACz) SAM on the indium tin oxide (ITO) substrate. The promoted adsorption is attributed to the enhanced tridentate binding between MeO‐2PACz and NiOx relative to the conventional bidentate binding between MeO‐2PACz and ITO. In addition, the NiOx modification can simultaneously improve the passivation ability and hole‐selectivity of the MeO‐2PACz, provide a favorable energy‐level alignment at the ITO/PVK interface, and prevent a direct contact between PVK and ITO. As a consequence, this NiOx‐seeded MeO‐2PACz hole transport layer enables a significantly enhanced power conversion efficiency of 19.9% in comparison with 18.4% of the control device. This work provides an effective strategy to improve the performance of the SAM‐based photoelectric device.
A sputtered NiOx seed layer is employed to promote the adsorption of 2‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)ethylphosphonic acid (MeO‐2PACz) self‐assembled monolayers. The resulting high‐density MeO‐2PACz provides an increased passivation, an enhanced hole‐selectivity, a favorable energy‐level alignment, and a robust physical contact between perovskite and indium tin oxide. The corresponding inverted perovskite solar cell exhibits an impressive efficiency of 19.9%.
Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia. At present, there are a ...variety of products, such as slurry monoammonium phosphate (MAP), diammonium phosphate (DAP), industrial grade MAP, water soluble MAP, water soluble ammonium polyphosphate (APP) and so on. After more than 60 years of development, China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong. The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore. The continuous, stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China. The development of new ammonium phosphate fertilizer products, such as industrial grade MAP, water soluble MAP, water soluble APP, provides technical support for the transformation and upgrading of phosphorus chemical enterprises. In this paper, the production methods, the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.
Two new enantiomerically chiral 3D architectures, l-(Zn(H2O)3)3MnMo9O32·4H2O and d-(Zn(H2O)3)3MnMo9O32·4H2O, have been produced from a new way. The compounds were composed of the discrete chiral ...MnMo9O326- polyoxoanions linked by zinc(II) atoms to a 3D framework with a 2-fold interpenetrating net, which is the first examples of POM-based chiral 3D frameworks consisting of only inorganic components.
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