The rice NUCLEAR FACTOR-YA5 and MICRORNA169a module promotes nitrogen utilization during nitrogen deficiency.

Nitrogen (N) is essential for plant growth and development. Therefore, understanding its utilization is essential for improving crop productivity. However, much remains to be learned about plant N sensing and signaling. Here, rice (Oryza sativa) NUCLEAR FACTOR-YA5 (OsNF-YA5) expression was tightly regulated by N status and induced under N-deficient conditions. Overexpression (OE) of OsNF-YA5 in rice resulted in increased chlorophyll levels and delayed senescence compared to control plants under normal N conditions. Agronomic traits were significantly improved in OE plants and impaired in knockout mutants under N-deficient conditions. Using a dexamethasone-inducible system, we identified the putative targets of OsNF-YA5 that include amino acid, nitrate/peptide transporters, and NITRATE TRANSPORTER 1.1A (OsNRT1.1A), which functions as a key transporter in rice. OsNF-YA5 directly enhanced OsNRT1.1A expression and N uptake rate under N-deficient conditions. Besides, overexpression of OsNF-YA5 also enhanced the expression of GLUTAMINE SYNTHETASE 1/2 (GS1/2) and GLUTAMINE OXOGLUTARATE AMINOTRANSFERASE 1/2 (GOGAT1/2), increasing free amino acid contents under N-deficient conditions. Osa-miR169a expression showed an opposite pattern with OsNF-YA5 depending on N status. Further analysis revealed that osa-miR169a negatively regulates OsNF-YA5 expression and N utilization, demonstrating that an OsNF-YA5/osa-miR169a module tightly regulates rice N utilization for adaptation to N status.

Enhanced Carrier Transport in Strongly Coupled, Epitaxially Fused CdSe Nanocrystal Solids.

Strongly coupled, epitaxially fused colloidal nanocrystal (NC) solids are promising solution-processable semiconductors to realize optoelectronic devices with high carrier mobilities. Here, we demonstrate sequential, solid-state cation exchange reactions to transform epitaxially connected PbSe NC thin films into Cu2Se nanostructured thin-film intermediates and then successfully to achieve zinc-blende, CdSe NC solids with wide epitaxial necking along {100} facets. Transient photoconductivity measurements probe carrier transport at nanometer length scales and show a photoconductance of 0.28(1) cm2 V-1 s-1, the highest among CdSe NC solids reported. Atomic-layer deposition of a thin Al2O3 layer infiltrates and protects the structure from fusing into a polycrystalline thin film during annealing and further improves the photoconductance to 1.71(5) cm2 V-1 s-1 and the diffusion length to 760 nm. We fabricate field-effect transistors to study carrier transport at micron length scales and realize high electron mobilities of 35(3) cm2 V-1 s-1 with on-off ratios of 106 after doping.

OsFKBP20-1b interacts with the splicing factor OsSR45 and participates in the environmental stress response at the post-transcriptional level in rice.

Sessile plants have evolved distinct mechanisms to respond and adapt to adverse environmental conditions through diverse mechanisms including RNA processing. While the role of RNA processing in the stress response is well understood for Arabidopsis thaliana, limited information is available for rice (Oryza sativa). Here, we show that OsFKBP20-1b, belonging to the immunophilin family, interacts with the splicing factor OsSR45 in both nuclear speckles and cytoplasmic foci, and plays an essential role in post-transcriptional regulation of abiotic stress response. The expression of OsFKBP20-1b was highly upregulated under various abiotic stresses. Moreover genetic analysis revealed that OsFKBP20-1b positively affected transcription and pre-mRNA splicing of stress-responsive genes under abiotic stress conditions. In osfkbp20-1b loss-of-function mutants, the expression of stress-responsive genes was downregulated, while that of their splicing variants was increased. Conversely, in plants overexpressing OsFKBP20-1b, the expression of the same stress-responsive genes was strikingly upregulated under abiotic stress. In vivo experiments demonstrated that OsFKBP20-1b directly maintains protein stability of OsSR45 splicing factor. Furthermore, we found that the plant-specific OsFKBP20-1b gene has uniquely evolved as a paralogue only in some Poaceae species. Together, our findings suggest that OsFKBP20-1b-mediated RNA processing contributes to stress adaptation in rice.

TGFam-Finder: a novel solution for target-gene family annotation in plants.

Whole-genome annotation error that omits essential protein-coding genes hinders further research. We developed Target Gene Family Finder (TGFam-Finder), an alternative tool for the structural annotation of protein-coding genes containing target domain(s) of interest in plant genomes. TGFam-Finder took considerably reduced annotation run-time and improved accuracy compared to conventional annotation tools. Large-scale re-annotation of 50 plant genomes identified an average of 150, 166 and 86 additional far-red-impaired response 1, nucleotide-binding and leucine-rich-repeat, and cytochrome P450 genes, respectively, that were missed in previous annotations. We detected significantly higher number of translated genes in the new annotations using mass spectrometry data from seven plant species compared to previous annotations. TGFam-Finder along with the new gene models can provide an optimized platform for comprehensive functional, comparative, and evolutionary studies in plants.

Efficient Capture and Raman Analysis of Circulating Tumor Cells by Nano-Undulated AgNPs-rGO Composite SERS Substrates.

The analysis of circulating tumor cells (CTCs) in the peripheral blood of cancer patients is critical in clinical research for further investigation of tumor progression and metastasis. In this study, we present a novel surface-enhanced Raman scattering (SERS) substrate for the efficient capture and characterization of cancer cells using silver nanoparticles-reduced graphene oxide (AgNPs-rGO) composites. A pulsed laser reduction of silver nanowire-graphene oxide (AgNW-GO) mixture films induces hot-spot formations among AgNPs and artificial biointerfaces consisting of rGOs. We also use in situ electric field-assisted fabrication methods to enhance the roughness of the SERS substrate. The AgNW-GO mixture films, well suited for the proposed process due to its inherent electrophoretic motion, is adjusted between indium tin oxide (ITO) transparent electrodes and the nano-undulated surface is generated by applying direct-current (DC) electric fields during the laser process. As a result, MCF7 breast cancer cells are efficiently captured on the AgNPs-rGO substrates, about four times higher than the AgNWs-GO films, and the captured living cells are successfully analyzed by SERS spectroscopy. Our newly designed bifunctional substrate can be applied as an effective system for the capture and characterization of CTCs.

Efficiency of Recombinant CRISPR/rCas9-Mediated miRNA Gene Editing in Rice.

Drought is one of the major environmental stresses adversely affecting crop productivity worldwide. Precise characterization of genes involved in drought response is necessary to develop new crop varieties with enhanced drought tolerance. Previously, we identified 66 drought-induced miRNAs in rice plants. For the further functional investigation of the miRNAs, we applied recombinant codon-optimized Cas9 (rCas9) for rice with single-guide RNAs specifically targeting mature miRNA sequences or sites required for the biogenesis of mature miRNA. A total of 458 T0 transgenic plants were analyzed to determine the frequency and type of mutations induced by CRISPR/rCas9 on 13 independent target miRNAs. The average mutation frequency for 13 genes targeted by single guide RNAs (sgRNAs) in T0 generation was 59.4%, including mono-allelic (8.54%), bi-allelic (11.1%), and hetero-allelic combination (39.7%) mutations. The mutation frequency showed a positive correlation with Tm temperature of sgRNAs. For base insertion, one base insertion (99%) was predominantly detected in transgenic plants. Similarly, one base deletion accounted for the highest percentage, but there was also a significant percentage of cases in which more than one base was deleted. The deletion of more than two bases in OsmiR171f and OsmiR818b significantly reduced the level of corresponding mature miRNAs. Further functional analysis using CRISPR/Cas9-mediated mutagenesis confirmed that OsmiR818b is involved in drought response in rice plants. Overall, this study suggests that the CRISPR/rCas9 system is a powerful tool for loss-of-function analysis of miRNA in rice.

General Synthetic Route to High-Quality Colloidal III-V Semiconductor Quantum Dots Based on Pnictogen Chlorides.

The synthesis of colloidal III-V quantum dots (QDs), particularly of the arsenides and antimonides, has been limited by the lack of stable and available group V precursors. In this work, we exploit accessible InCl3- and pnictogen chloride-oleylamine as precursors to synthesize III-V QDs. Through coreduction reactions of the precursors, we achieve size- and stoichiometry-tunable binary InAs and InSb as well as ternary alloy InAs1-xSbx QDs. On the basis of structural, analytical, optical, and electrical characterization of the QDs and their thin-film assemblies, we study the effects of alloying on their particle formation and optoelectronic properties. We introduce a hydrazine-free hybrid ligand-exchange process to improve carrier transport in III-V QD thin films and realize InAs QD field-effect transistors with electron mobility > 5 cm2/(V s). We demonstrate that III-V QD thin films are promising candidate materials for infrared devices and show InAs1-xSbx QD photoconductors with superior short-wavelength infrared (SWIR) photoresponse than those of the binary QD devices.

Label-free high-resolution 3-D imaging of gold nanoparticles inside live cells using optical diffraction tomography.

Delivery of gold nanoparticles (GNPs) into live cells has high potentials, ranging from molecular-specific imaging, photodiagnostics, to photothermal therapy. However, studying the long-term dynamics of cells with GNPs using conventional fluorescence techniques suffers from phototoxicity and photobleaching. Here, we present a method for 3-D imaging of GNPs inside live cells exploiting refractive index (RI) as imaging contrast. Employing optical diffraction tomography, 3-D RI tomograms of live cells with GNPs are precisely measured for an extended period with sub-micrometer resolution. The locations and contents of GNPs in live cells are precisely addressed and quantified due to their distinctly high RI values, which was validated by confocal fluorescence imaging of fluorescent dye conjugated GNPs. In addition, we perform quantitative imaging analysis including the segmentations of GNPs in the cytosol, the volume distributions of aggregated GNPs, and the temporal evolution of GNPs contents in HeLa and 4T1 cells.

ELK3-GATA3 axis modulates MDA-MB-231 metastasis by regulating cell-cell adhesion-related genes.

GATA3 is a master regulator that drives mammary epithelial cell differentiation, and the suppression of GATA3 expression is associated with the development of aggressive breast cancer. However, the mechanism through which GATA3 loss drives cancer development is poorly understood. Previously, we reported that ELK3 suppression in MDA-MB-231 (ELK3 KD) resulted in the reprogramming of these cells from a basal to luminal subtype, which was associated with the induction of GATA3 expression, and that the ELK3-GATA3 axis orchestrated the metastatic characteristics of MDA-MB-231. Here, we show that GATA3 suppression in ELK3 knockdown MDA-MB-231 cells (ELK3/GATA3 DKD) restores the metastatic ability comparably to that of control MDA-MB-231 cells, even though the epithelial cell morphology and TGF-ß signaling of ELK3 KD are not recovered in ELK3/GATA3 DKD. The expression of E-cadherin and tight junctional proteins, including occludin, claudin and ZO-1, which is activated in ELK3 KD, is suppressed in ELK3/GATA3 DKD. These results reveal the possibility that the ELK3-GATA3 axis determines the metastatic characteristics of MDA-MB-231 by regulating the expression of cell-cell adhesion factors.

Reduced Graphene Oxide/LiI Composite Lithium Ion Battery Cathodes.

Li-iodine chemistry is of interest for electrochemical energy storage because it has been shown to provide both high power and high energy density. However, Li-iodine batteries are typically formed using Li metal and elemental iodine, which presents safety and fabrication challenges (e.g., the high vapor pressure of iodine). These disadvantages could be circumvented by using LiI as a starting cathode. Here, we present fabrication of a reduced graphene oxide (rGO)/LiI composite cathode, enabling for the first time the use of LiI as the Li-ion battery cathode. LiI was coated on rGO by infiltration of an ethanolic solution of LiI into a compressed rGO aerogel followed by drying. The free-standing rGO/LiI electrodes show stable long-term cycling and good rate performance with high specific capacity (200 mAh g-1 at 0.5 C after 100 cycles) and small hysteresis (0.056 V at 1 C). Shuttling was suppressed significantly. We speculate the improved electrochemical performance is due to strong interactions between the active materials and rGO, and the reduced ion and electron transport distances provided by the three-dimensional structured cathode.

The role of ELK3 to regulate peritumoral lymphangiogenesis and VEGF-C production in triple negative breast cancer cells.

Tumor-induced lymphangiogenesis, a major conduit for cancer cell dissemination from the primary tumor site to lymph nodes and beyond, eventually leads to metastasis in cancer patients. Given the recent evidence revealing that the suppression of ELK3 inhibits the metastasis of triple-negative breast cancer cells, we aimed to study the underlying mechanism of impaired metastasis in ELK3-suppressed MDA-MB-231 cells (ELK3 KD) with regard to lymphangiogenesis. We found that the secretome of ELK3 KD cells inhibited tube formation, whereas it promoted the migration and invasion of lymphatic endothelial cells (LECs) in vitro. In vivo analysis revealed that peritumoral lymphatic vessels were not developed around the xenografted tumors of ELK3 KD. We further revealed that the suppression of NF-κB signaling in ELK3 KD was the primary cause of the reduced VEGFC expression. Taken together, we suggest that ELK3 is an upstream regulator of the NF-κB signaling pathway, the inhibition of which leads to the suppression of peritumoral lymphatic vessel development, possibly due to a low VEGFC expression.

Metal Oleate Induced Etching and Growth of Semiconductor Nanocrystals, Nanorods, and Their Heterostructures.

Unexpected etching of nanocrystals, nanorods, and their heterostructures by one of the most commonly used metal precursors, metal oleates, is reported. Zn oleate is shown to etch CdS nanorods anisotropically, where the length decreases without a significant change in the diameter. Sodium oleate enhances the etch rate, whereas oleic acid alone does not cause etching, indicating the importance of the countercation on the rate of oleate induced etching. Subsequent addition of Se precursors to the partially etched nanorods in Zn oleate solution can lead to epitaxial growth of CdSe particles rather than the expected ZnSe growth, despite an excess amount of Zn precursors being present. The composition of this epitaxial growth can be varied from CdSe to ZnSe, depending on the amount of excess oleic acid or the reaction temperature. Similar tuning of composition can be observed when starting with collinear CdSe/CdS/CdSe rod/rod/rod heterostructures and spherical CdS (or CdSe/CdS core/shell) nanocrystals. Conversion of collinear rod/rod/rod structures to barbells and interesting rod growth from nearly spherical particles among other structures can also result due to the initial etching effect of metal oleates. These observations have important implications on our understanding of nanocrystal heterostructure synthesis and open up new routes to varying the composition and morphology of these materials.

High-resolution patterns of quantum dots formed by electrohydrodynamic jet printing for light-emitting diodes.

Here we demonstrate materials and operating conditions that allow for high-resolution printing of layers of quantum dots (QDs) with precise control over thickness and submicron lateral resolution and capabilities for use as active layers of QD light-emitting diodes (LEDs). The shapes and thicknesses of the QD patterns exhibit systematic dependence on the dimensions of the printing nozzle and the ink composition in ways that allow nearly arbitrary, systematic control when exploited in a fully automated printing tool. Homogeneous arrays of patterns of QDs serve as the basis for corresponding arrays of QD LEDs that exhibit excellent performance. Sequential printing of different types of QDs in a multilayer stack or in an interdigitated geometry provides strategies for continuous tuning of the effective, overall emission wavelengths of the resulting QD LEDs. This strategy is useful to efficient, additive use of QDs for wide ranging types of electronic and optoelectronic devices.

The spatiotemporal development of adipose tissue.

Adipose tissue is a structure highly specialized in energy storage. The adipocyte is the parenchymal component of adipose tissue and is known to be mesoderm or neuroectoderm in origin; however, adipocyte development remains poorly understood. Here, we investigated the development of adipose tissue by analyzing postnatal epididymal adipose tissue (EAT) in mouse. EAT was found to be generated from non-adipose structure during the first 14 postnatal days. From postnatal day 1 (P1) to P4, EAT is composed of multipotent progenitor cells that lack adipogenic differentiation capacity in vitro, and can be regarded as being in the 'undetermined' state. However, the progenitor cells isolated from P4 EAT obtain their adipogenic differentiation capacity by physical interaction generated by cell-to-matrix and cell-to-cell contact both in vitro and in vivo. In addition, we show that impaired angiogenesis caused by either VEGFA blockade or macrophage depletion in postnatal mice interferes with adipose tissue development. We conclude that appropriate interaction between the cellular and matrix components along with proper angiogenesis are mandatory for the development of adipose tissue.

Dual-wavelength band spectroscopic optical frequency domain imaging using plasmon-resonant scattering in metallic nanoparticles.

We demonstrate a dual-wavelength band optical frequency domain imaging (OFDI) system that provides high-resolution spectroscopic imaging with metallic nanoparticles as exogenous contrast agents. The local increase of the OFDI signal by elastic scattering from two different custom-fabricated nonspherical nanoparticles resonant at each wavelength band of the system was successfully detected, and we were able to distinguish and visualize the location of each of the nanoparticles in a scattering sample and in biological tissue.

Cytotoxicity of amine-modified polystyrene MPs and NPs on neural stem cells cultured from mouse subventricular zone.

Microplastics (MPs) and nanoplastics (NPs) are found in various environments such as aquatic, terrestrial, and aerial areas. Once ingested and inhaled, these tiny plastic debris damaged the digestive and respiratory organ systems in animals. In humans, the possible connection between MPs and various diseases such as lung diseases has been raised. Yet, the impact of MPs on the human nervous system has been unclear. Previous research using animals and cultured cells showed possible neurotoxicity of MPs and NPs. In this study, we used neural stem cells cultured from mouse subventricular zone to examine the effects of polystyrene (PS) NPs and MPs with sizes of 0.1 µm, 1 µm, and 2 µm on the cell proliferation and differentiation. We observed that only positively charged NPs and MPs, but not negatively charged ones, decreased cell viability and proliferation. These amine-modified NPs and MPs decreased both neurogenesis and oligodendrogenesis. Finally, fully differentiated neurons and oligodendrocytes were damaged and removed by the application of NPs and MPs. All these effects varied among different sizes of NPs and MPs, with the greatest effects from 1 µm and the least effects from 2 µm. These results clearly demonstrate the cytotoxicity and neurotoxicity of PS-NPs and MPs.

Tailoring photobiomodulation to enhance tissue regeneration.

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Colloidal Synthesis of P-Type Zn3As2 Nanocrystals.

Zinc pnictides, particularly Zn3As2, hold significant promise for optoelectronic applications owing to their intrinsic p-type behavior and appropriate bandgaps. However, despite the outstanding properties of colloidal Zn3As2 nanocrystals, research in this area is lacking because of the absence of suitable precursors, occurrence of surface oxidation, and intricacy of the crystal structures. In this study, a novel and facile solution-based synthetic approach is presented for obtaining highly crystalline p-type Zn3As2 nanocrystals with accurate stoichiometry. By carefully controlling the feed ratio and reaction temperature, colloidal Zn3As2 nanocrystals are successfully obtained. Moreover, the mechanism underlying the conversion of As precursors in the initial phases of Zn3As2 synthesis is elucidated. Furthermore, these nanocrystals are employed as active layers in field-effect transistors that exhibit inherent p-type characteristics with native surface ligands. To enhance the charge transport properties, a dual passivation strategy is introduced via phase-transfer ligand exchange, leading to enhanced hole mobilities as high as 0.089 cm2 V-1 s-1. This study not only contributes to the advancement of nanocrystal synthesis, but also opens up new possibilities for previously underexplored p-type nanocrystal research.

Subcellular distribution of the rAAV genome depends on genome structure.

Many studies have been conducted on the transduction efficiency of recombinant adeno-associated virus (rAAV) depending on the serotype and genome structure, such as single-stranded (ss) and self-complementary (sc). To understand the variation in therapeutic efficacy, we focused on investigating subcellular distribution of viral genome depending on rAAV genome structure. It is critical to ascertain the location of the virus within the host cell after the entry because a larger amount of the viral genome placed in the nucleus facilitates viral genome replication by utilizing the host cell's system, thereby enhancing the therapeutic outcome. In this sense, tracking the location of the virus within the host cell's organelles can inform a new strategy to improve therapeutic efficacy. Therefore, we attempted to stain only the viral genome with APEX2 and DAB chemicals specifically, and the distribution of the viral genome was examined by transmission electron microscopy (TEM). Consequently, when the two types of rAAV were transduced for 6 h, scAAV2 tended to be more located in the lysosome and nucleus compared to ssAAV2.

Ligand-Crosslinking Strategy for Efficient Quantum Dot Light-Emitting Diodes via Thiol-Ene Click Chemistry.

While solution-processable colloidal quantum dots (QDs) offer cost-effective and large-scale manufacturing, they can be susceptible to subsequent solution processes, making continuous processing challenging. To enable complex and integrated device architectures, robust QD films with subsequent patterning are necessary. Here, we report a facile ligand-crosslinking strategy based on thiol-ene click chemistry. Thiol molecules added to QD films react with UV light to form radicals that crosslink with QD ligands containing carbon double bonds, enabling microscale photo-patterning of QD films and enhancing their solvent resistance. This strategy can also be extended to other ligand-capped nanocrystals. It is found that the swelling of QD films during the process of binding with the thiol molecules placed between the ligands contributes to the improvement of photoluminescence and electroluminescence properties. These results suggest that the thiol-ene crosslinking modifies the optoelectronic properties and enables direct optical patterning, expanding the potential applications of QDs.