White organic light‐emitting diodes (WOLEDs) with thermally activated delayed fluorophor sensitized fluorescence (TSF) have aroused wide attention, considering their potential for full exciton ...utilization without noble‐metal containing phosphors. However, performances of TSF‐WOLEDs with a single‐emissive‐layer (SEL) still suffer from low exciton utilization and insufficient blue emission for proper white balance. Here, by modulating Förster and Dexter interactions in SEL‐TSF‐WOLEDs, high efficiencies, balanced white spectra, and extended lifetimes are realized simultaneously. Given the different dependencies of Förster and Dexter interactions on intermolecular distances, sterically shielded blue thermally activated delayed fluorescence (TADF) emitters and orange conventional fluorescent dopants (CFDs) with electronically inert peripheral units are adopted to enlarge distances of electronically active chromophores, not only blocking the Dexter interaction to prevent exciton loss but also finely suppressing the Förster one to guarantee balanced white emission with sufficient blue components. It thus provides the possibility to maximize device performances in a large range of CFD concentrations. A record high maximum external quantum efficiency/power efficiency of 19.6%/52.2 lm W−1, Commission Internationale de L'Eclairage coordinate of (0.33, 0.45), and prolonged half‐lifetime of over 2300 h at an initial luminance of 1000 cd m−2 are realized simultaneously for SEL‐TSF‐WOLEDs, paving the way toward practical applications.
Single‐emissive‐layer all fluorescent white organic light‐emitting diodes yield a record high external quantum efficiency of 19.6%, power efficiency of 52.2 lm W−1, and long half‐lifetime of 2304 h simultaneously, by blending a sterically shielded blue emitter with thermally activated delayed fluorescence and orange conventional fluorescent dopants to modulate exciton interactions.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Research on image retrieval and classification in the food field has become one of the more and more concerned research topics in the field of multimedia analysis and applications. In recent years, ...with the rapid development of the Internet industry and multimedia technology, image classification and retrieval technology has become a research hotspot at home and abroad. Traditional keyword-based image retrieval and image classification have been unable to meet people’s daily needs; so, image recognition methods based on image content came into being. The most representative of image feature description methods are mainly two aspects: image visual features and image abstract semantics extracted based on machine learning algorithms. These two algorithms have their own key points in describing images, which are difficult to achieve the desired results in image classification and image retrieval. Based on this, this paper proposes research on food image classification and image retrieval methods based on visual features and machine learning. This paper proposes a food image retrieval and classification method based on Faster R-CNN network. This paper selects food image sets from the visual gene database to fine-tune the Faster R-CNN network to ensure the accuracy of Faster R-CNN food area detection, and experimented on the Dish-233 food dataset, which is a subset of the dish dataset, including 233 dishes and 49,168 images. The experimental results in this paper show that the performance of this method is better than other methods in terms of image classification performance. Compared with CNN-GF, the performance is improved by 5%. In terms of image retrieval, this method also shows its superiority This proves that compared with other methods, the proposed method has more discriminative visual features, and its performance has been improved in food image retrieval and classification tasks.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Summary
CRISPR‐Cpf1 is a newly identified CRISPR‐Cas system, and Cpf1 was recently engineered as a molecular tool for targeted genome editing in mammalian cells. To test whether the engineered ...CRISPR‐Cpf1 system could induce the production of rice mutants, we selected two genome targets in the OsPDS and OsBEL genes. Our results show that both targets could be efficiently mutated in transgenic rice plants using CRISPR‐Cpf1. We found that pre‐crRNAs with a full‐length direct repeat sequence exhibited considerably increased efficiencies compared with mature crRNAs. In addition, the specificity and transmission of the mutation were investigated, and the behaviours of crRNA‐Cpf1‐induced plant targeted genome mutagenesis were assessed. Taken together, our results indicate that CRISPR‐Cpf1 expression via stable transformation can efficiently generate specific and heritable targeted mutations in rice and thereby constitutes a novel and important approach to specific and precise plant genome editing.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has lasted more than 2 years with over 260 million infections and 5 million deaths worldwide as of November 2021. To combat ...the virus, monoclonal antibodies blocking the virus binding to human receptor, the angiotensin converting enzyme 2 (ACE2), have been approved to treat the infected patients. Inactivated whole virus or the full-length virus spike encoding adenovirus or mRNA vaccines are being used to immunize the public. However, SARS-CoV-2 variants are emerging. These, to some extent, escape neutralization by the therapeutic antibodies and vaccine-induced immunity. Thus, breakthrough infections by SARS-CoV-2 variants have been reported in previously virus-infected or fully vaccinated individuals. The receptor binding domain (RBD) of the virus spike protein reacts with host ACE2, leading to the entry of the virus into the cell. It is also the major antigenic site of the virus, with more than 90% of broadly neutralizing antibodies from either infected patients or vaccinated individuals targeting the spike RBD. Therefore, mutations in the RBD region are effective ways for SARS-CoV-2 variants to gain infectivity and escape the immunity built up by the original vaccines or infections. In this review, we focus on the impact of RBD mutations in SARS-CoV-2 variants of concern (VOC) and variants of interest (VOI) on ACE2 binding affinity and escape of serum antibody neutralization. We also provide protein structure models to show how the VOC and VOI RBD mutations affect ACE2 binding and allow escape of the virus from the therapeutic antibody, bamlanivimab.
N-doping is an effective way to increase the electron conductivity of organic semiconductors and achieve ohmic cathode contacts in organic electronics. To avoid the use of difficult-to-handle highly ...reactive n-dopants, air-stable precursors are widely used nowadays, which could decompose to release reactive species in a subtractive way though always with unwanted and even harmful byproducts during processing. Here, we show that air-stable metals, such as copper, silver and gold, could release free electrons readily in the presence of chelating ligands, as the irreversible coordination reaction between metal ions and the ligands would push the equilibrium between metals and metal ions to the forward direction. By using a well-designed multi-functional electron transport material with a strong nucleophilic quality, 4,7-dimethoxy-1,10-phenanthroline (p-MeO-Phen), silver could function as an n-dopant stronger than cesium and could be used to fabricate organic light-emitting diodes with higher performance than the cesium-doped control device.
The security of digital image attracts much attention recently. In Guan et al. Guan Z, Huang F, Guan W. Chaos-based image encryption algorithm. Phys Lett A 2005; 346: 153–7., a chaos-based image ...encryption algorithm has been proposed. In this paper, the cause of potential flaws in the original algorithm is analyzed in detail, and then the corresponding enhancement measures are proposed. Both theoretical analysis and computer simulation indicate that the improved algorithm can overcome these flaws and maintain all the merits of the original one.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
Low efficiency has seriously restricted the application of prime editing (PE) systems in plants. In this study, we develop an enhanced plant prime editor 2 system, enpPE2, by stacking ...various optimization strategies, including updating the PE architecture to PEmax and expressing engineered pegRNA with a structured motif under the control of a composite promoter. In T
0
rice plants, enpPE2 exhibits editing frequencies of 64.58% to 77.08%, which are much higher than the frequencies with unmodified pPE2. Our results indicate that the enpPE2 system provides a robust and powerful tool for the precise modification of plant genomes.
Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex ...traits depends on the combination of beneficial alleles at the quantitative trait loci (QTLs). However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Plane segmentation is a basic yet important process in light detection and ranging (LiDAR) point cloud processing. The traditional point cloud plane segmentation algorithm is typically affected by ...the number of point clouds and the noise data, which results in slow segmentation efficiency and poor segmentation effect. Hence, an efficient encoding voxel-based segmentation (EVBS) algorithm based on a fast adjacent voxel search is proposed in this study. First, a binary octree algorithm is proposed to construct the voxel as the segmentation object and code the voxel, which can compute voxel features quickly and accurately. Second, a voxel-based region growing algorithm is proposed to cluster the corresponding voxel to perform the initial point cloud segmentation, which can improve the rationality of seed selection. Finally, a refining point method is proposed to solve the problem of under-segmentation in unlabeled voxels by judging the relationship between the points and the segmented plane. Experimental results demonstrate that the proposed algorithm is better than the traditional algorithm in terms of computation time, extraction accuracy, and recall rate.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK