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The morphology of 75 different pollen grains from 67 species of genus Solanum L., two species of genus Cyphomandra Sendt., and six species of genus Lycianthes (Dunal) Hassl. was studied using light microscopy and scanning electron microscopy. Among them, the pollen of 66 species is described for the first time. Our results suggest that the sexine ornamention of Solanum, Cyphomandra and Lycianthes is extremely similar, but the apertures of genus Solanum and Cyphomandra are not syncolpate while those of genus Lycianthes are syncolpate. Overall, we argued that the Solanum species studied demonstrated sufficient pollinic heterogeneity in their shapes, aperture feature and sexine ornamentation to enable their palynological characterisation and support the point of view that the genus Cyphomandra should be merged into Solanum, but Lycianthes should be an independent genus from the aspect of palynology.

The pollen morphology of 54 species and one variety of seven genera in Polygonatae including Clintonia, Disporopsis, Disporum, Maianthemum, Polygonatum, Smilacina and Streptopus was observed and studied in detail; of these, nine species were reported for the first time. Our results showed that the surface ornamentation of pollen grains of the studied materials could be divided into seven types, namely gemmate, granulate-foveolate, perforate, reticulate, rugulate, rugulate-perforate and verrucate. In line with previous studies, we believe that (i) Smilacina ginfushanicum should be classified into the genus Heteropolygonatum rather than the genus Smilacina; (ii) Polygonatum should be divided into section Polygonatum and section Verticillata; (iii) Smilacina and Maianthemum should be combined as one genus, i.e. Maianthemum sensu lato; and (iv) Clintonia, Disporum and Streptopus should be separated from the tribe Polygonatae.

Uniform silver-containing metal nanostructures with well-defined nanogaps hold great promise for ultrasensitive surface-enhanced Raman scattering （SERS） analyses. Nevertheless, the direct synthesis of such nanostructures with strong and stable SERS signals remains extremely challenging. Here, we report a DNA-mediated approach for the direct synthesis of gold-silver nano-mushrooms with interior nanogaps. The SERS intensities of these nano-mushrooms were critically dependent on the area of the nanogap between the gold head and the silver cap. We found that the formation of nanogaps was finely tunable by controlling the surface density of 6-carboxy-X-rhodamine （ROX） labeled single-stranded DNA （ssDNA） on the gold nanoparticles. We obtained nano-mushrooms in high yield with a high SERS signal enhancement factor of -1.0×109, much higher than that for Au-Ag nanostructures without nanogaps. Measurements for single nano- mushrooms show that these structures have both sensitive and reproducible SERS signals.

Autophagy is a basic cellular process that decomposes damaged organelles and aberrant proteins. Dysregulation of autophagy is implicated in pathogenesis of neurodegenerative disorders, including Parkinson＇s disease（PD）. Pharmacological compounds that stimulate autophagy can provide neuroprotection in models of PD. Nanoparticles have emerged as regulators of autophagy and have been tested in adjuvant therapy for diseases. In this present study, we explore the effects of quantum dots（QDs） that can induce autophagy in a cellular model of Parkinson＇s disease. Cd Te/Cd S/Zn S QDs protect differentiated rat pheochromocytoma PC12 cells from MPP＋-induced cell damage, including reduced viability, apoptosis and accumulation of α-Synuclein, a characteristic protein of PD. The protective function of QDs is autophagy-dependent. In addition, we investigate the interaction between quantum dots and autophagic pathways and identify beclin1 as an essential factor for QDs-induced autophagy. Our results reveal new promise of QDs in the theranostic of neurodegenerative diseases.

Contemporary industrial equipment is increasingly developing towards complexity. In order to ensure the high reliability and sustainability of industrial equipment, more flexible maintenance strategies have attracted extensive attention. In view of this, this paper aims to summarize the current situation of existing maintenance strategies, so as to enable colleagues in the industry to choose or formulate more efficient maintenance strategies. Firstly, the characteristics, application potential and limitations of single component maintenance strategies, such as corrective maintenance, preventive maintenance and predictive maintenance, are described in detail from the perspective of maintenance time. On the basis of single component maintenance and the dependency between multiple components, the advantages and disadvantages of multicomponent maintenance strategies, such as batch maintenance, opportunity maintenance and group maintenance, are summarized, and suggestions for the future maintenance of industrial equipment are proposed. Based on this, industries can select the appropriate maintenance strategy according to their equipment characteristics, or improve their existing maintenance strategies based on actual needs.

Signal amplification in biological systems is achieved by cooperatively recruiting multiple copies of regulatory biomolecules. Nevertheless, the multiplexing capability of artificial fluorescent amplifiers is limited due to the size limit and lack of modularity. Here, we develop Cayley tree-like fractal DNA frameworks to topologically encode the fluorescence states for multiplexed detection of low-abundance targets. Taking advantage of the self-similar topology of Cayley tree, we use only 16 DNA strands to construct n-node (n = 53) structures of up to 5 megadalton. The high level of degeneracy allows encoding 36 colours with 7 nodes by site-specifically anchoring of distinct fluorophores onto a structure. The fractal topology minimises fluorescence crosstalk and allows quantitative decoding of quantized fluorescence states. We demonstrate a spectrum of rigid-yet-flexible super-multiplex structures for encoded fluorescence detection of single-molecule recognition events and multiplexed discrimination of living cells. Thus, the topological engineering approach enriches the toolbox for high-throughput cell imaging. Though DNA framework-based scaffolds for biomolecular assembly are attractive for bioimaging applications, realizing super-multiplex fluorescent amplifiers remains a challenge. Here, the authors report a topological engineering approach to designing fractal DNA frameworks for multiplexed amplifiers.

The past decades have witnessed the evolution of electronic and photonic integrated circuits, from application specific to programmable 1 , 2 . Although liquid-phase DNA circuitry holds the potential for massive parallelism in the encoding and execution of algorithms 3 , 4 , the development of general-purpose DNA integrated circuits (DICs) has yet to be explored. Here we demonstrate a DIC system by integration of multilayer DNA-based programmable gate arrays (DPGAs). We find that the use of generic single-stranded oligonucleotides as a uniform transmission signal can reliably integrate large-scale DICs with minimal leakage and high fidelity for general-purpose computing. Reconfiguration of a single DPGA with 24 addressable dual-rail gates can be programmed with wiring instructions to implement over 100 billion distinct circuits. Furthermore, to control the intrinsically random collision of molecules, we designed DNA origami registers to provide the directionality for asynchronous execution of cascaded DPGAs. We exemplify this by a quadratic equation-solving DIC assembled with three layers of cascade DPGAs comprising 30 logic gates with around 500 DNA strands. We further show that integration of a DPGA with an analog-to-digital converter can classify disease-related microRNAs. The ability to integrate large-scale DPGA networks without apparent signal attenuation marks a key step towards general-purpose DNA computing. Generic single-stranded oligonucleotides used as a uniform transmission signal can reliably integrate large-scale DNA integrated circuits with minimal leakage and high fidelity for general-purpose computing.

DNA origami is capable of spatially organizing molecules into sophisticated geometric patterns with nanometric precision. Here we describe a reconfigurable, two-dimensional DNA origami with geometrically patterned CD95 ligands that regulates immune cell signalling to alleviate rheumatoid arthritis. In response to pH changes, the device reversibly transforms from a closed to an open configuration, displaying a hexagonal pattern of CD95 ligands with ~10 nm intermolecular spacing, precisely mirroring the spatial arrangement of CD95 receptor clusters on the surface of immune cells. In a collagen-induced arthritis mouse model, DNA origami elicits robust and selective activation of CD95 death-inducing signalling in activated immune cells located in inflamed synovial tissues. Such localized immune tolerance ameliorates joint damage with no noticeable side effects. This device allows for the precise spatial control of cellular signalling, expanding our understanding of ligand–receptor interactions and is a promising platform for the development of pharmacological interventions targeting these interactions. A pH-responsive DNA origami device displays a precise geometric array of CD95 ligands to selectively induce activated immune cell death and elicit localized immune tolerance to alleviate rheumatoid arthritis.

A molecular classification of diseases that accurately reflects clinical behaviour lays the foundation of precision medicine. The development of in silico classifiers coupled with molecular implementation based on DNA reactions marks a key advance in more powerful molecular classification, but it nevertheless remains a challenge to process multiple molecular datatypes. Here we introduce a DNA-encoded molecular classifier that can physically implement the computational classification of multidimensional molecular clinical data. To produce unified electrochemical sensing signals across heterogeneous molecular binding events, we exploit DNA-framework-based programmable atom-like nanoparticles with n valence to develop valence-encoded signal reporters that enable linearity in translating virtually any biomolecular binding events to signal gains. Multidimensional molecular information in computational classification is thus precisely assigned weights for bioanalysis. We demonstrate the implementation of a molecular classifier based on programmable atom-like nanoparticles to perform biomarker panel screening and analyse a panel of six biomarkers across three-dimensional datatypes for a near-deterministic molecular taxonomy of prostate cancer patients. The authors use a DNA-framework-based molecular classifier to perform biomarker panel screening and analyse six biomarkers across three-dimensional datatypes to obtain a molecular taxonomy for prostate cancer diagnosis.

Reporter systems are routinely used in plant genetic engineering and functional genomics research. Most such plant reporter systems cause accumulation of foreign proteins. Here, we demonstrate a protein-independent reporter system, 3WJ-4 × Bro, based on a fluorescent RNA aptamer. Via transient expression assays in both Escherichia coli and Nicotiana benthamiana , we show that 3WJ-4 × Bro is suitable for transgene identification and as an mRNA reporter for expression pattern analysis. Following stable transformation in Arabidopsis thaliana , 3WJ-4 × Bro co-segregates and co-expresses with target transcripts and is stably inherited through multiple generations. Further, 3WJ-4 × Bro can be used to visualize virus-mediated RNA delivery in plants. This study demonstrates a protein-independent reporter system that can be used for transgene identification and in vivo dynamic analysis of mRNA. Fluorescent RNA aptamers could potentially be used as protein-independent reporters of transgene expression in plants. Here, the authors report that an optimized RNA aptamer, developed from Broccoli, can be used to detect transgene expression in stable and transiently transformed plant tissue.