T-DNA insertion in Arabidopsis caused coexisting chromosomal inversion and duplication at megabase level.

Agrobacteria-mediated transformation is widely used in plant genetic engineering to introduce exogenous genes and create mutant lines through random T-DNA insertion and gene disruption. When T-DNA fragments are inserted into the plant genome, it could cause chromosomal abnormalities. In this study, we investigated the genetic basis of pleiotropic phenotypes observed in the T-DNA insertion mutant lnc161. We discovered that there are four T-DNA insertions present in the lnc161 genome, which disrupted the genes LNC161 (AT3G05035), AT3G57400, AT5G05630, and AT5G16450, respectively. However, none of these insertions were the causative mutation that leads to the lnc161 phenotypes. Strikingly, through genetic analyses and high throughput sequencing, we found an inversion of about 19.8 Mb sequences between LNC161 and AT3G57400. Moreover, the sequences between AT5G05630 and AT5G16450 (about 3.7 Mb) were translocated from chromosome 5 to chromosome 3, adjacent to the inversion sequences, and were duplicated. This duplication led to an up-regulation of genes expression in this region, potentially resulting in pleiotropic morphological traits in lnc161. Overall, this study provides a case showing complex chromosomal re-arrangement induced by T-DNA insertion.

A repertoire of intronic lariat RNAs reveals tissue-specific regulation and target mimicry potential in plants.

Lariat RNA is concomitantly produced by excised intron during RNA splicing, which is usually debranched by DBR1, an RNA debranching enzyme. However, increasing evidence showed that some lariat RNA could escape debranching. Little is known about how and why these lariat RNAs could be retained. By comparing the atlas of lariat RNAs between the non-dividing cell (mature pollen) and three actively dividing tissues (young shoot apex, young seeds, and young roots), we identified hundreds to thousands of lariat RNA naturally retained in each tissue, and the incidence of lariat RNA retention is much less in shoot apex while much more in pollen. Many lariat RNAs derived from the same intron or different lariat RNAs from the same pre-mRNA could be retained in one tissue while degraded in the other tissues. By deciphering lariat RNA sequences, we identified an AG-rich (RAAAAVAAAR) motif and a UC-rich (UCUCUYUCUC) motif for pollen-specific and the other three tissues-retained lariat RNAs, respectively. Reconstitution of the pollen-specific AG-rich motif indeed enhanced lariat RNA retention in plants. Biologically, hundreds of lariat RNAs harbored miRNA binding sites, and dual-luciferase reporter assay showed that these natural lariat RNAs had the potential to protect expression of miRNA target genes. Collectively, our results uncover that selective retention of lariat RNA is an actively regulatory process, and provide new insights into understanding how lariat RNA metabolism may impact miRNA activity.

Giant Modulation of Refractive Index from Picoscale Atomic Displacements.

It is shown that structural disorder-in the form of anisotropic, picoscale atomic displacements-modulates the refractive index tensor and results in the giant optical anisotropy observed in BaTiS3, a quasi-1D hexagonal chalcogenide. Single-crystal X-ray diffraction studies reveal the presence of antipolar displacements of Ti atoms within adjacent TiS6 chains along the c-axis, and threefold degenerate Ti displacements in the a-b plane. 47/49Ti solid-state NMR provides additional evidence for those Ti displacements in the form of a three-horned NMR lineshape resulting from a low symmetry local environment around Ti atoms. Scanning transmission electron microscopy is used to directly observe the globally disordered Ti a-b plane displacements and find them to be ordered locally over a few unit cells. First-principles calculations show that the Ti a-b plane displacements selectively reduce the refractive index along the ab-plane, while having minimal impact on the refractive index along the chain direction, thus resulting in a giant enhancement in the optical anisotropy. By showing a strong connection between structural disorder with picoscale displacements and the optical response in BaTiS3, this study opens a pathway for designing optical materials with high refractive index and functionalities such as large optical anisotropy and nonlinearity.

Photonic Properties of Thin Films Composed of Gallium Nitride Quantum Dots Synthesized by Nonequilibrium Plasma Aerotaxy.

Gallium nitride quantum dots (GaN QDs) are a promising material for optoelectronics, but the synthesis of freestanding GaN QDs remains a challenge. To date, the size-dependent photonic properties of freestanding GaN QDs have not been reported. Here, we examine the photonic properties exhibited by thin films composed of GaN QDs synthesized by nonequilibrium plasma aerotaxy. Each film exhibited two photoluminescence peaks after exposure to ambient air. The first peak was in the ultraviolet spectral region, and the second peak was in the visible region. Both peak positions depended on the QD size. Our findings, supported by transient absorption spectroscopy experiments, suggest that conduction band to valence band recombination was the cause of the ultraviolet photoluminescence and that recombination between the conduction band and an acceptor level was the cause of visible photoluminescence. Furthermore, we show that coating the surface of fresh QDs with Al2O3 suppressed the visible region photoluminescence, corroborating the conclusion that the photoactive defect was caused by oxidation in air.

The adult, pupa, and larva of a new species of Gnaptorina Reitter, 1887 (Coleoptera, Tenebrionidae, Blaptini) from the Tibetan Plateau, with molecular phylogenetic inferences.

The adult, pupa and larva of a new species, Gnaptorina (Gnaptorina) lhorongica Li, sp. nov., from northeastern Xizang, China are described and illustrated. The species was identified using molecular phylogenetic analyses based on three mitochondrial fragments and one nuclear gene fragment (COI, Cytb, 16S, and 28S-D2). The taxonomic status of the new species is confirmed using a combination of molecular and morphological datasets. This study provides valuable molecular and morphological data for phylogenetic studies of the tribe Blaptini.

Review of the genus Laena Dejean, 1821 (Coleoptera, Tenebrionidae) from Gansu Province, China, with the description of a new species.

A new species of the genus Laena from Xiaolongshan in Gansu Province, China is described as Laenahuisp. nov. All Laena species known to occur in Gansu Province are reviewed, and an identification key is provided. The mitochondrial gene COI to confirm the identity of the new species, which is morphologically most similar and phylogenetically close to L.fengileana. The new species can be recognized by features of elytra and tibiae.

A Josephson junction-coupled neuron with double capacitive membranes.

The channel currents have distinct magnetic field effect and any changes of the electromagnetic field or electirc stimulus will change the membrane potential effectively. A feasible neuron model considers the distinct physical characteristic is more suitable to mimic the neural activities accompanying with shift in energy level. A Josephson junction (JJ) is connected to a neural circuit for estimating the effect of external magnetic field and two capacitors are connected via a linear resistor for mimicing the capacitive field beside two sides of the cell membrane. Its equivalent Hamilton energy is calculated to show the relation between firing mode and energy level. Noisy disturbance is imposed to predict the occurrence of coherence resonance, and the biophysical neuron is excited to present higher energy level. This new neuron model can address the field effect and the biophysical property of cell membrane considered as combination of capacitive fields in double capacitors. It can mimic the physical property of outer and inner membranes, and energy exchange across the double membranes explains the energy mechanism in neural activities. Time-varying energy diveristy between capacitive field is crucial for supporting continuous firing activities. The JJ channel discerns slight changes in external magnetic field and regularity is stabilized under coherence resonance in presence of noisy excitation on the membrane or ion channels.

Catalysts Prepared from Atomically Dispersed Ce(III) on MgO Rival Bulk Ceria for CO Oxidation.

Atomically dispersed cerium catalysts on an inert, crystalline MgO powder support were prepared by using both Ce(III) and Ce(IV) precursors. The materials were used as catalysts for CO oxidation in a once-through flow reactor and characterized by atomic-resolution scanning transmission electron microscopy, X-ray absorption near-edge structure spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed reduction, among other techniques, before and after catalysis. The most active catalysts, formed from the precursor incorporating Ce(III), displayed performance similar to that reported for bulk ceria under comparable conditions. The catalyst provided stable time-on-stream performance for as long as it was kept on-stream, 2 days, increasing slightly in activity as the atomically dispersed cerium ions were transformed into ceria nanodomains represented as CeOx and having increased reducibility on the MgO support. The results suggest how highly dispersed supported ceria catalysts with low cerium loadings can be prepared and may pave the way for improved efficiencies of cerium utilization in oxidation catalysis.

Uloma (Uloma) intricornicula Liu, Ren & Wang, 2007 (Coleoptera, Tenebrionidae, Ulomini): Descriptions of the larva and pupa and new distributional records.

Background: The genus Uloma Dejean, 1821 (Coleoptera, Tenebrionidae, Ulomini) comprises more than 200 species and subspecies worldwide, 37 of which are recorded from China. However, the morphology of the immature stages of Chinese Uloma have been poorly documented. Up to now, larva and pupa descriptions are available for only one species, Uloma (Uloma) metogana Ren, 2004. New information: The larva and pupa of Uloma (Uloma) intricornicula Liu, Ren & Wang, 2007, from southern China, are described and illustrated for the first time and are compared with those of U. (U.) metogana Ren, 2004. Differences between male and female pupae of this species are highlighted. New distributional data for U. (U.) intricornicula are also provided. Finally, 13 Uloma species from China are formally assigned to the nominated subgenus.

Charge Density Wave Order and Electronic Phase Transitions in a Dilute d-Band Semiconductor.

As one of the most fundamental physical phenomena, charge density wave (CDW) order predominantly occurs in metallic systems such as quasi-1D metals, doped cuprates, and transition metal dichalcogenides, where it is well understood in terms of Fermi surface nesting and electron-phonon coupling mechanisms. On the other hand, CDW phenomena in semiconducting systems, particularly at the low carrier concentration limit, are less common and feature intricate characteristics, which often necessitate the exploration of novel mechanisms, such as electron-hole coupling or Mott physics, to explain. In this study, an approach combining electrical transport, synchrotron X-ray diffraction, and density-functional theory calculations is used to investigate CDW order and a series of hysteretic phase transitions in a dilute d-band semiconductor, BaTiS3 . These experimental and theoretical findings suggest that the observed CDW order and phase transitions in BaTiS3 may be attributed to both electron-phonon coupling and non-negligible electron-electron interactions in the system. This work highlights BaTiS3 as a unique platform to explore CDW physics and novel electronic phases in the dilute filling limit and opens new opportunities for developing novel electronic devices.

Two new species of the genus Laena (Coleoptera, Tenebrionidae, Lagriinae) from northern Sichuan in China based on morphological and molecular data.

In this study, the Laena species from northern Sichuan Province were reviewed using a combination of molecular and morphological datasets. Three molecular methods for species delimitation were firstly used in the genus Laena to explore species boundaries. The results show that the number of morphospecies and putative species using Automatic Barcode Gap Discovery (ABGD) is consistent. Based on the results, two new species are described and illustrated: Laenamounigouicasp. nov. and Laenadentithoraxasp. nov. New materials and distribution of 10 Laena species are also provided in this study. This work also provides valuable molecular data for species identification and phylogenetic analyses of the genus Laena and subfamily Lagriinae.

Colossal Optical Anisotropy from Atomic-Scale Modulations.

Materials with large birefringence (Δn, where n is the refractive index) are sought after for polarization control (e.g., in wave plates, polarizing beam splitters, etc.), nonlinear optics, micromanipulation, and as a platform for unconventional light-matter coupling, such as hyperbolic phonon polaritons. Layered 2D materials can feature some of the largest optical anisotropy; however, their use in most optical systems is limited because their optical axis is out of the plane of the layers and the layers are weakly attached. This work demonstrates that a bulk crystal with subtle periodic modulations in its structure-Sr9/8 TiS3 -is transparent and positive-uniaxial, with extraordinary index ne = 4.5 and ordinary index no = 2.4 in the mid- to far-infrared. The excess Sr, compared to stoichiometric SrTiS3 , results in the formation of TiS6 trigonal-prismatic units that break the chains of face-sharing TiS6 octahedra in SrTiS3 into periodic blocks of five TiS6 octahedral units. The additional electrons introduced by the excess Sr form highly oriented electron clouds, which selectively boost the extraordinary index ne and result in record birefringence (Δn > 2.1 with low loss). The connection between subtle structural modulations and large changes in refractive index suggests new categories of anisotropic materials and also tunable optical materials with large refractive-index modulation.

Tumor Cell Targeting and Responsive Nanoplatform for Multimodal-Imaging Guided Chemodynamic/Photodynamic/Photothermal Therapy toward Triple Negative Breast Cancer.

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with ineffective treatment and poor prognosis. It is in great demand to develop a novel theranostic strategy for accurate diagnosis and targeted treatment of TNBC. In the present study, one nanoplatform (HA-ICG-Fe-PDA), endowed with multimodal imaging-guided chemodynamic/photodynamic/photothermal (CDT/PDT/PTT) synergistic therapy capacity toward TNBC, was innovatively constructed. The nanoplatform was prepared by covalently conjugating ICG-decorated hyaluronic acid (HA) on Fe3+-chelated polydopamine (PDA). HA facilitated the targeting and accumulating of the nanoplatform in tumor tissue and cells of TNBC, thus producing enhanced magnetic resonance signal. Upon entering into TNBC cells, the intracellular hyaluronidase-catalyzed cleavage of HA-ICG-Fe-PDA activated the prequenched near-infrared (NIR) fluorescence signal, allowing for the activatable NIR fluorescence imaging. On the other hand, Fe3+ in the nanoplatform could be reduced to reactive Fe2+ in tumor microenvironment, guaranteeing efficient Fenton reaction-mediated CDT. The combination of ICG with Fe-PDA enhanced the NIR absorption of the nanoplatform so that considerable PTT/PDT and photothermal imaging were achieved under 808 nm laser irradiation. In vitro and in vivo experiments have verified that the proposed nanoplatform integrates the potential of TNBC-targeting, precise NIR fluorescence/magnetic resonance/photothermal trimodal imaging, efficient treatment via synergistic CDT/PDT/PTT, as well as excellent biocompatibility. Therefore, this multifunctional nanoplatform provides a simple and versatile strategy for imaging-guided theranostics of TNBC.

Revision of the genus Colasia Koch, 1965 (= Belousovia Medvedev, 2007, syn. nov.) (Coleoptera, Tenebrionidae, Blaptini).

The relationship between the genera Colasia Koch, 1965 and Belousovia Medvedev, 2007 within the tribe Blaptini is discussed, and a new synonymy is proposed: Belousovia Medvedev, 2007, syn. nov. of Colasia Koch, 1965. As a result, three new combinations are established: Colasiahelenae (Medvedev, 2007), comb. nov., C.kabakiintermedia (Medvedev, 2007), comb. nov., and C.kabakikabaki (Medvedev, 2007), comb. nov.Colasiaakisoides Koch, 1965 is redescribed, and a lectotype is designated. Three new species of the genus Colasia are described and illustrated from China: C.bijicasp. nov. (Guizhou), C.medvedevisp. nov. (Yunnan), and C.pilosasp. nov. (Yunnan). A distribution map and a key to species of the revised genus Colasia are presented.

The Adult and Larva of a New Species of the Genus Dila (Coleoptera, Blaptinae, Blaptini) from Himalayas, with Molecular Phylogenetic Inferences of Related Genera of the Blaptini.

In this study, a new species of the genus Dila Fischer von Waldheim, 1844, D. ngaria Li and Ren sp. n., was described from the southwestern Himalayas. The adult and larva were associated using molecular phylogenetic analyses based on fragments of three mitochondrial and one nuclear gene fragment (COI, Cytb, 16S and 28S-D2). Additionally, a preliminary phylogenetic tree was reconstructed and discussed based on a molecular dataset with seven related genera and 24 species of the tribe Blaptini. Meanwhile, the monophyly of the subtribe Dilina and the taxonomic status of D. bomina Ren and Li, 2001 are discussed. This work provides new molecular data for phylogenetic studies on the tribe Blaptini in the future.

Targeted chemo-photodynamic therapy toward esophageal cancer by GSH-sensitive theranostic nanoplatform.

As the sixth leading cause of cancer death, esophageal cancer is threatening the life of people worldwide. Traditional treatments, such as surgery, chemotherapy, radiotherapy, are facing always augmented challenges including invasion, multidrug resistance (MDR), off-target toxicity. Chemo & Photodynamic synergistic therapy represents one promising strategy for improved treatment efficiency. But it is still hindered by the lack of tumor targeting, deleterious side effects, and unfavorable microenvironment for photodynamic therapy (PDT). To overcome those obstacles, one theranostic nano-assambly drug, GCDs-Ce6/Pt-EGF, was designed and fabricated. Green fluorescence carbon dots (GCDs) with the excellent optical properties, modifiability and low toxicity were prepared as drug carrier. Epidermal growth factor (EGF) was conjugated to the nano-assembly to realize tumor specific targeting. Chlorin e6 (Ce6) in the presence of laser irradiation achieved PDT by generating proapoptosis reactive oxygen species (ROS). Moreover, Ce6 incorporated into GCDs endowed the nano-assambly imaging ability and facilitate image-guided therapy. Pt(IV), cisplatin prodrug, in the nano-assambly depleted the glutathione (GSH) of tumor microenvironment when it was reduced to cytotoxicity Pt(II). Compared with single treatment, GCDs-Ce6/Pt-EGF exhibited enhanced tumor cell killing capacity and better biosafety in vitro and in vivo, especially for EGFR bearing tumor. It paved ways for developing novel theranostic agent to be potentially applied in clinic.

Uridylation and the SKI complex orchestrate the Calvin cycle of photosynthesis through RNA surveillance of TKL1 in Arabidopsis.

RNA uridylation, catalyzed by terminal uridylyl transferases (TUTases), represents a conserved and widespread posttranscriptional RNA modification in eukaryotes that affects RNA metabolism. In plants, several TUTases, including HEN1 SUPPRESSOR 1 (HESO1) and UTP: RNA URIDYLYLTRANSFERASE (URT1), have been characterized through genetic and biochemical approaches. However, little is known about their physiological significance during plant development. Here, we show that HESO1 and URT1 act cooperatively with the cytoplasmic 3'-5' exoribonucleolytic machinery component SUPERKILLER 2 (SKI2) to regulate photosynthesis through RNA surveillance of the Calvin cycle gene TRANSKETOLASE 1 (TKL1) in Arabidopsis. Simultaneous dysfunction of HESO1, URT1, and SKI2 resulted in leaf etiolation and reduced photosynthetic efficiency. In addition, we detected massive illegitimate short interfering RNAs (siRNAs) from the TKL1 locus in heso1 urt1 ski2, accompanied by reduced TKL1/2 expression and attenuated TKL activities. Consequently, the metabolic analysis revealed that the abundance of many Calvin cycle intermediates is dramatically disturbed in heso1 urt1 ski2. Importantly, all these molecular and physiological defects were largely rescued by the loss-of-function mutation in RNA-DEPENDENT RNA POLYMERASE 6 (RDR6), demonstrating illegitimate siRNA-mediated TKL silencing. Taken together, our results suggest that HESO1- and URT1-mediated RNA uridylation connects to the cytoplasmic RNA degradation pathway for RNA surveillance, which is crucial for TKL expression and photosynthesis in Arabidopsis.

Molecular mechanism underlying the di-uridylation activity of Arabidopsis TUTase URT1.

In Arabidopsis, HESO1 and URT1 act cooperatively on unmethylated miRNA and mRNA uridylation to induce their degradation. Their collaboration significantly impacts RNA metabolism in plants. However, the molecular mechanism determining the functional difference and complementarity of these two enzymes remains unclear. We previously solved the three-dimensional structure of URT1 in the absence and presence of UTP. In this study, we further determined the structure of URT1 in complex with a 5'-AAAU-3' RNA stretch that mimics the post-catalytic state of the mRNA poly(A) tail after the addition of the first uridine. Structural analysis and enzymatic assays revealed that L527 and Y592 endow URT1 with a preference to interact with purine over pyrimidine at the -1 RNA binding position, thus controlling the optimal number of uridine added to the 3' extremity of poly(A) as two. In addition, we observed that a large-scale conformational rearrangement in URT1 occurs upon binding with RNA from an 'open' to a 'closed' state. Molecular dynamic simulation supports an open-closed conformational selection mechanism employed by URT1 to interact with RNA substrates and maintain distributive enzymatic activity. Based on the above results, a model regarding the catalytic cycle of URT1 is proposed to explain its di-uridylation activity.

Spontaneous Seed Formation during Electrodeposition Drives Epitaxial Growth of Metastable Bismuth Selenide Microcrystals.

Materials with metastable phases can exhibit vastly different properties from their thermodynamically favored counterparts. Methods to synthesize metastable phases without the need for high-temperature or high-pressure conditions would facilitate their widespread use. We report on the electrochemical growth of microcrystals of bismuth selenide, Bi2Se3, in the metastable orthorhombic phase at room temperature in aqueous solution. Rather than direct epitaxy with the growth substrate, the spontaneous formation of a seed layer containing nanocrystals of cubic BiSe enforces the metastable phase. We first used single-crystal silicon substrates with a range of resistivities and different orientations to identify the conditions needed to produce the metastable phase. When the applied potential during electrochemical growth is positive of the reduction potential of Bi3+, an initial, Bi-rich seed layer forms. Electron microscopy imaging and diffraction reveal that the seed layer consists of nanocrystals of cubic BiSe embedded within an amorphous matrix of Bi and Se. Using density functional theory calculations, we show that epitaxial matching between cubic BiSe and orthorhombic Bi2Se3 can help stabilize the metastable orthorhombic phase over the thermodynamically stable rhombohedral phase. The spontaneous formation of the seed layer enables us to grow orthorhombic Bi2Se3 on a variety of substrates including single-crystal silicon with different orientations, polycrystalline fluorine-doped tin oxide, and polycrystalline gold. The ability to stabilize the metastable phase through room-temperature electrodeposition in aqueous solution without requiring a single-crystal substrate broadens the range of applications for this semiconductor in optoelectronic and electrochemical devices.