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Large-scale genomic variations are fundamental resources for crop genetics and breeding. Here we sequenced 1,904 genomes of broomcorn millet to an average of 40× sequencing depth and constructed a comprehensive variation map of weedy and cultivated accessions. Being one of the oldest cultivated crops, broomcorn millet has extremely low nucleotide diversity and remarkably rapid decay of linkage disequilibrium. Genome-wide association studies identified 186 loci for 12 agronomic traits. Many causative candidate genes, such as PmGW8for grain size and PmLG1for panicle shape, showed strong selection signatures during domestication. Weedy accessions contained many beneficial variations for the grain traits that are largely lost in cultivated accessions. Weedy and cultivated broomcorn millet have adopted different loci controlling flowering time for regional adaptation in parallel. Our study uncovers the unique population genomic features of broomcorn millet and provides an agronomically important resource for cereal crops.

Cobalt-rich crusts (CRCs) are an extremely important deep-sea mineral resource. In order to promote the commercial exploitation of CRCs, the thickness measurement of deep-sea CRCs is of great significance. In order to measure the thickness of CRCs in a reverberation environment, a low-power and high-performance underwater thickness measuring system was built. The system has strong penetration ability and measurement resolution. For strong reverberation and low signal-to-noise ratio signals, a wavelet threshold denoising (WTD) evaluation method was proposed by wavelet time–frequency analysis based on the multilayer medium echo characteristics when pure signals cannot be obtained. It is convenient for the selection of optimal parameters of WTD. The WTD removed the high-frequency reverberation noise and improved the echo quality. A hybrid algorithm for transmission time estimation was proposed by combining the advantages of adaptive echo matching (AEM) and envelope peak. We solved the multilayer medium echo interference by intercepting the echo through the envelope peak thresholding. The results show that the algorithm can efficiently and accurately process the echo signals with low noise interference and calculate the transmission time of the echoes. The ultrasonic thickness measuring system and signal processing method in this article is an effective method to measure the thickness of CRCs.

Soft robots based on particle jamming cannot return to the initial position and initial mechanical state due to the accumulation of particles after removing the particle jamming, which means poor restorability, and the compliance of the robots during deformation will be reduced because of the jamming effect. Here, we present the design, fabrication, and tests of a novel soft actuator with good restorability and compliance. To improve the restorability of the actuator, we used cotton threads to connect the spherical acrylic beads into form strings instead of discrete beads. The beads could be pulled to the initial position by the threads, the actuator also returns to the initial state. To avoid the jamming effect during the deformation of the actuator, we used compressed air to drive the actuator and injected the beads into the actuator after the active deformation. To reduce the driving pressure and facilitate the flow of the beads, an initial noncontact, frame-type strain constraint structure was designed for the soft actuator. Experimental data show that the actuator was flexible during bending and the stiffness can increase more than 12-fold to resist the external load. By pulling the threads, the actuator could be restored to the initial state with an error of less than 3% of the actuator length after an operation cycle. The soft gripper based on the actuator can grasp repeatedly or laterally. The gripper can grasp soft objects such as a piece of tofu and a balloon of water, and the maximum weight that can be stably grasped is 2.744 kg.

Pressure ulcer prevention is very necessary for patients with limited movement. Human sleeping posture recognition algorithm is the key technology of intelligent pressure ulcer prevention equipment. In this article, a sleeping pressure image acquisition system is designed. Based on the data collected by the system, we innovatively propose a trunk centerline prediction algorithm based on 1-D Gaussian template. The average prediction deviation of the algorithm is 1.10 pixels (the actual equivalent distance is 1.27 cm). Statistics show that the algorithm has high accuracy for volunteers with different shapes. In addition, we propose a new correction algorithm for sleeping pressure image, which can effectively improve the accuracy of the subsequent sleeping posture recognition algorithm. Finally, the cumulative pressure value of the sleeping pressure images in the vertical direction is extracted as the feature, and a support vector machine (SVM) with sigmoid kernel is used to classify the three basic sleeping postures. Its classification accuracy is up to 97.2%.

A complete telomere-to-telomere (T2T) finished genome has been the long pursuit of genomic research. Through generating deep coverage ultralong Oxford Nanopore Technology (ONT) and PacBio HiFi reads, we report here a complete genome assembly of maize with each chromosome entirely traversed in a single contig. The 2,178.6 Mb T2T Mo17 genome with a base accuracy of over 99.99% unveiled the structural features of all repetitive regions of the genome. There were several super-long simple-sequence-repeat arrays having consecutive thymine–adenine–guanine (TAG) tri-nucleotide repeats up to 235 kb. The assembly of the entire nucleolar organizer region of the 26.8 Mb array with 2,974 45S rDNA copies revealed the enormously complex patterns of rDNA duplications and transposon insertions. Additionally, complete assemblies of all ten centromeres enabled us to precisely dissect the repeat compositions of both CentC-rich and CentC-poor centromeres. The complete Mo17 genome represents a major step forward in understanding the complexity of the highly recalcitrant repetitive regions of higher plant genomes.

ABSTRACTUnintended effects of genetically modified (GM) crops may pose safety issues. Omics techniques provide researchers with useful tools to assess such unintended effects. Proteomics and metabolomics analyses were performed for three GM maize varieties, 2A-7, CC-2, and 2A-7×CC-2 stacked transgenic maize, and the corresponding non-GM parent Zheng58.Proteomics revealed 120, 271 and 135 maize differentially expressed proteins (DEPs) in the 2A-7/Zheng58, CC-2/Zheng58 and 2A-7×CC-2/Zheng58 comparisons, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that most DEPs participated in metabolic pathways and the biosynthesis of secondary metabolite. Metabolomics revealed 179, 135 and 131 differentially accumulated metabolites (DAMs) in the 2A-7/Zheng58, CC-2/Zheng58 and 2A-7×CC-2/Zheng58 comparisons, respectively. Based on KEGG enrichment analysis, most DAMs are involved in the biosynthesis of secondary metabolite and metabolic pathways. According to integrated proteomics and metabolomics analysis, the introduction of exogenous EPSPS did not affect the expression levels of six other enzymes or the abundance of seven metabolites involved in the shikimic acid pathway in CC-2 and 2A-7×CC-2 seeds. Six co-DEPs annotated by integrated proteomics and metabolomics pathway analysis were further analyzed by qRT-PCR.This study successfully employed integrated proteomic and metabolomic technology to assess unintended changes in maize varieties. The results suggest that GM and gene stacking do not cause significantly unintended effects.

Doubled haploid technology has been widely applied to multiple plant species and is recognized as one of the most important technologies for improving crop breeding efficiency. Although mutations in MATRILINEAL/Zea mays PHOSPHOLIPASE A1/NOT LIKE DAD(MTL/ZmPLA1/NLD) and Zea mays DOMAIN OF UNKNOWN FUNCTION 679 MEMBRANE PROTEIN(ZmDMP) have been shown to generate haploids in maize, knowledge of the genetic basis of haploid induction (HI) remains incomplete. Therefore, cloning of new genes underlying HI is important for further elucidating its genetic architecture. Here, we found that loss-of-function mutations of Zea mays PHOSPHOLIPASE D3(ZmPLD3), one of the members from the phospholipase D subfamily, could trigger maternal HI in maize. ZmPLD3was identified through a reverse genetic strategy based on analysis of pollen-specifically expressed phospholipases, followed by validation through the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR–Cas9) system. Mutations of ZmPLD3resulted in a haploid induction rate (HIR) similar to that of mtl/zmpla1/nldand showed synergistic effects rather than functional redundancy on tripling the HIR (from 1.19% to 4.13%) in the presence of mtl/zmpla1/nld. RNA-seq profiling of mature pollen indicated that a large number of pollen-specific differentially expressed genes were enriched in processes related to gametogenesis development, such as pollen tube development and cell communication, during the double-fertilization process. In addition, ZmPLD3is highly conserved among cereals, highlighting the potential application of these in vivo haploid-inducer lines for other important crop plant species. Collectively, our discovery identifies a novel gene underlying in vivo maternal HI and provides possibility of breeding haploid inducers with further improved HIR.

Surface acoustic wave (SAW) resonators with an ultrahigh Q-factor are designed and fabricated on silicon-based gallium nitride (GaN/Si). The temperature-dependent performance is characterized over a wide range, from 10 to 500 K. Finite element analysis is employed to guide the design of the SAW resonator from indications of the Rayleigh mode and weak propagation direction dependence of SAW in the c-plane of GaN/Si. The SAW resonator with 100 pairs of interdigital transducers (IDT), 100 pairs of grating reflectors (GR) for each side, aperture size of 80 µm, metallization ratio of 0.5, and electrode width of 500 nm resonates at 1.9133 GHz accordingly with an ultrahigh Q-factor of 7622 at room temperature, which contributes the fr× Qr, up to 14.583×1012Hz. A resonator operating over 10 to 500 K indicates an approximately linear decreasing temperature dependence above 280 K while being approximately constant below 40 K. The fitting to resonator characteristics using the modified Butterworth Van Dyke (mBVD) model reveals a reduction in both the electrode and mechanical losses while worsening the dielectric loss with cooling down.

Since 1989, three-dimensional (3D) printing has developed rapidly in biomedical engineering because it is individually customizable. By printing medical products at clinics, this powerful tool can be used by doctors, which will enhance the response to surgery and increase the creative freedom of surgeons. In this article, we reviewed the progress of 3D printing in biomedicine with particular emphasis on the types of 3D printing methods that are most suitable for the clinical application, and proposed the concept of Printing@clinic. The four levels of Printing@clinic are discussed, from surgical implants to direct printing during surgery. Three major applications of Printing@clinic, which could be rapidly implemented in the clinical setting, are fabricating prosthesis to assist with surgeries, printing 3D implantable scaffolds, and bioprinting for tissue repair. We believe that Printing@clinic will be an attractive service in the decades to come.

In recent years, 3D integrated microfluidic systems have become increasingly more popular because of their ability to incorporate multifunctional components, including porous membranes and biological scaffolds. Because of limitations in resolution, fabrication efficiency and materials, it is hard to develop complex integrated microfluidic systems with low cost and high efficiency. In this paper, we present a novel method that utilizes modular structure-based design, which could greatly reduce the time and cost for customization of complete integrated chips, compared to traditional techniques. By printing sacrificial patterns on the substrate using the 3D printing approach and subsequently covering them with PDMS prepolymer, PDMS slices with modular structures were obtained, each with specific functions. By combining different PDMS slices with specific modular structures and other functional components, such as membranes and scaffolds, the conceptual design was efficiently converted into complete integrated microfluidic chips. As proof-of-concept, customized 3D microfluidic chips were generated and successfully used for cell culture and biological analysis. Furthermore, the flexible combination with biofabrication of hydrogel beads was also presented, revealing the potential use of this technique in the fabrication of organ-on-a-chip.

Maize is an important crop with a high level of genome diversity and heterosis. The genome sequence of a typical female line, B73, was previously released. Here, we report a de novo genome assembly of a corresponding male representative line, Mo17. More than 96.4% of the 2,183 Mb assembled genome can be accounted for by 362 scaffolds in ten pseudochromosomes with 38,620 annotated protein-coding genes. Comparative analysis revealed large gene-order and gene structural variations: approximately 10% of the annotated genes were mutually nonsyntenic, and more than 20% of the predicted genes had either large-effect mutations or large structural variations, which might cause considerable protein divergence between the two inbred lines. Our study provides a high-quality reference-genome sequence of an important maize germplasm, and the intraspecific gene order and gene structural variations identified should have implications for heterosis and genome evolution.

Genomic imprinting refers to allele-specific expression of genes depending on their parental origin. Nucleosomes, the fundamental units of chromatin, play a critical role in gene transcriptional regulation. However, it remains unknown whether differential nucleosome organization is related to the allele-specific expression of imprinted genes. Here, we generated a genome-wide map of allele-specific nucleosome occupancy in maize endosperm and presented an integrated analysis of its relationship with parent-of-origin-dependent gene expression and DNA methylation. We found that ∼2.3% of nucleosomes showed significant parental bias in maize endosperm. The parent-of-origin-dependent nucleosomes mostly exist as single isolated nucleosomes. Parent-of-origin-dependent nucleosomes were significantly associated with the allele-specific expression of imprinted genes, with nucleosomes positioned preferentially in the promoter of nonexpressed alleles of imprinted genes. Furthermore, we found that most of the paternal specifically positioned nucleosomes (pat-nucleosomes) were associated with parent-of-origin-dependent differential methylated regions, suggesting a functional link between the maternal demethylation and the occurrence of pat-nucleosome. Maternal specifically positioned nucleosomes (mat-nucleosomes) were independent of allele-specific DNA methylation but seem to be associated with allele-specific histone modification. Our study provides the first genome-wide map of allele-specific nucleosome occupancy in plants and suggests a mechanistic connection between chromatin organization and genomic imprinting.

CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins) is an adaptive immune system in bacteria and archaea to defend against invasion from foreign DNA fragments. Recently, it has been developed as a powerful targeted genome editing tool for a wide variety of species. However, its application in maize has only been tested with transiently expressed somatic cells or with a limited number of stable transgenic T0plants. The exact efficiency and specificity of the CRISPR/Cas system in the highly complex maize genome has not been documented yet. Here we report an extensive study of the well-studied type II CRISPR-Cas9 system for targeted genome editing in maize, with the codon-optimized Cas9 protein and the short non-coding guide RNA generated through a functional maize U6snRNA promoter. Targeted gene mutagenesis was detected for 90 loci by maize protoplast assay, with an average cleavage efficiency of 10.67%. Stable knockout transformants for maize phytoene synthase gene (PSY1) were obtained. Mutations occurred in germ cells can be stably inherited to the next generation. Moreover, no off-target effect was detected at the computationally predicted putative off-target loci. No significant difference between the transcriptomes of the Cas9 expressed and non-expressed lines was detected. Our results confirmed that the CRISPR-Cas9 could be successfully applied as a robust targeted genome editing system in maize.

The three-row and four-column slewing bearing is used as the slewing guarantee for large equipment, such as TBM. This particular structure provides an improvement in the bearing capacity, meanwhile, it also has different behaviors compared to conventional roller slewing bearing. In order to pay attention to different roller design parameters and axial clearance for the effect on its roller safety factor, specific analysis tools must be developed. First, this paper presents a set of load distribution and contact stress analytical method based on the actual contact behavior, and FEM is used to assure its reliability. Secondly, the influence of different roller crownings on the generatrix contact stress is analyzed by using the proposed method, and the optimization algorithms get involved in improving the roller crowning and reduce the max contact stress by about 5%. Finally, taking the roller safety factor as the evaluation index, the orthogonal experiment is carried out with 6 key design parameters, and their influence characteristics and priorities are analyzed.

Understanding the growth mechanism of graphene layers in chemical vapor deposition (CVD) and their corresponding Raman properties is technologically relevant and of importance for the application of graphene in electronic and optoelectronic devices. Here, we report CVD growth of single-crystal trilayer graphene (TLG) grains on Cu and show that lattice defects at the center of each grain persist throughout the growth, indicating that the adlayers share the same nucleation site with the upper layers and these central defects could also act as a carbon pathway for the growth of a new layer. Statistics shows that ABA, 30–30, 30–AB, and AB–30 make up the major stacking orientations in the CVD-grown TLG, with distinctive Raman 2D characteristics. Surprisingly, a high level of lattice defects results whenever a layer with a twist angle of θ = 30° is found in the multiple stacks of graphene layers.

DNA sequencing is vital for many aspects of biological research and diagnostics. Despite the development of second- and third-generation sequencing technologies, Sanger sequencing has long been the only choice when required to precisely track each sequenced plasmids or DNA fragments. Here, we report a complete set of novel barcoding and assembling system, Highly-parallel Indexed Tagmentation-reads Assembled Consensus sequencing (HITAC-seq), that could massively sequence and track the identities of each individual sequencing sample. With the cost of much less than that of single read of Sanger sequencing, HITAC-seq can generate high-quality contiguous sequences of up to 10 kilobases or longer. The capability of HITAC-seq was confirmed through large-scale sequencing of thousands of plasmid clones and hundreds of amplicon fragments using approximately 100 pg of input DNAs. Due to its long synthetic length, HITAC-seq was effective in detecting relatively large structural variations, as demonstrated by the identification of a ∼1.3 kb Copiaretrotransposon insertion in the upstream of a likely maize domestication gene. Besides being a practical alternative to traditional Sanger sequencing, HITAC-seq is suitable for many high-throughput sequencing and genotyping applications.

In this study, a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/n-Si hybrid solar cell is fabricated via spin coating and treatment with HNO3vapor. It is found that after the HNO3treatment, the hybrid solar cell shows much better performance with an open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (?) of 555.34 mV, 23.61 mA/cm2, 0.54, and 8.81%, respectively. The conversion efficiency is nearly two times larger than that before HNO3treatment. The possible reason is that HNO3could significantly reduce the resistivity of the spin-coated PEDOT:PSS. The effect of HNO3treatment time on the PEDOT:PSS/n-Si HSC's performance is also investigated.