Firmly anchored photosensitizer Chlorin e6 to layered double hydroxide nanoflakes for highly efficient photodynamic therapy in vivo

We covalently conjugate photosensitizer Chlorin e6 (Ce6) to polyethylene glycol modified layered double hydroxides and produce hybrid nanoflakes with excellentin vivophotodynamic therapeutic efficiency and safety profiles.</p

Convergence of the 26S proteasome and the REVOLUTA pathways in regulating inflorescence and floral meristem functions in Arabidopsis

The 26S proteasome is a large multisubunit proteolytic complex, regulating growth and development in eukaryotes by selective removal of short-lived regulatory proteins. Here, it is shown that the 26S proteasome and the transcription factor gene REVOLUTA (REV) act together in maintaining inflorescence and floral meristem (IM and FM) functions. The characterization of a newly identified Arabidopsis mutant, designated ae4 (asymmetric leaves1/2 enhancer4), which carries a mutation in the gene encoding the 26S proteasome subunit, RPN2a, is reported. ae4 and rev have minor defects in phyllotaxy structure and meristem initiation, respectively, whereas ae4 rev demonstrated strong developmental defects. Compared with the rev single mutant, an increased percentage of ae4 rev plants exhibited abnormal vegetative shoot apical and axillary meristems. After flowering, ae4 rev first gave rise to a few normal-looking flowers, and then flowers with reduced numbers of all types of floral organs. In late reproductive development, instead of flowers, the ae4 rev IM produced numerous filamentous structures, which contained cells seen only in the floral organs, and then carpelloid organs. In situ hybridization revealed that expression of the WUSCHEL and CLAVATA3 genes was severely down-regulated or absent in the late appearing ae4 rev primordia, but the genes were strongly expressed in top-layer cells of inflorescence tips. Double mutant plants combining rev with other 26S proteasome subunit mutants, rpn1a and rpn9a, resembled ae4 rev, suggesting that the 26S proteasome might act as a whole in regulating IM and FM functions

miR396-targeted AtGRF transcription factors are required for coordination of cell division and differentiation during leaf development in Arabidopsis

In plants, cell proliferation and polarized cell differentiation along the adaxial–abaxial axis in the primordium is critical for leaf morphogenesis, while the temporal–spatial relationships between these two processes remain largely unexplored. Here, it is reported that microRNA396 (miR396)-targeted Arabidopsis growth-regulating factors (AtGRFs) are required for leaf adaxial–abaxial polarity in Arabidopsis. Reduction of the expression of AtGRF genes by transgenic miR396 overexpression in leaf polarity mutants asymmetric leaves1 (as1) and as2 resulted in plants with enhanced leaf adaxial–abaxial defects, as a consequence of reduced cell proliferation. Moreover, transgenic miR396 overexpression markedly decreased the cell division activity and the expression of cell cycle-related genes, but resulted in an increased percentage of leaf cells with a higher ploidy level, indicating that miR396 negatively regulates cell proliferation by controlling entry into the mitotic cell cycle. miR396 is mainly expressed in the leaf cells arrested for cell division, coinciding with its roles in cell cycle regulation. These results together suggest that cell division activity mediated by miR396-targeted AtGRFs is important for polarized cell differentiation along the adaxial–abaxial axis during leaf morphogenesis in Arabidopsis

Overexpression of Saussurea involucrata dehydrin gene SiDHN promotes cold and drought tolerance in transgenic tomato plants.

Dehydrins are late embryogenesis abundant proteins that help regulate abiotic stress responses in plants. Overexpression of the Saussurea involucrata dehydrin gene SiDHN has previously been shown to improve water-use efficiency and enhance cold and drought tolerance of transgenic tobacco. To understand the mechanism by which SiDHN exerts its protective function, we transformed the SiDHN gene into tomato plants (Solanum lycopersicum L.) and assessed their response to abiotic stress. We observed that in response to stresses, the SiDHN transgenic tomato plants had increased contents of chlorophyll a and b, carotenoid and relative water content compared with wild-type plants. They also had higher maximal photochemical efficiency of photosystem II and accumulated more proline and soluble sugar. Compared to those wild-type plants, malondialdehyde content and relative electron leakage in transgenic plants were not significantly increased, and H2O2 and O2- contents in transgenic tomato plants were significantly decreased. We further observed that the production of stress-related antioxidant enzymes, including superoxide dismutase, ascorbate peroxidase, peroxidase, and catalase, as well as pyrroline-5-carboxylate synthetase and lipid transfer protein 1, were up-regulated in the transgenic plants under cold and drought stress. Based on these observations, we conclude that overexpression of SiDHN gene can promote cold and drought tolerance of transgenic tomato plants by inhibiting cell membrane damage, protecting chloroplasts, and enhancing the reactive oxygen species scavenging capacity. The finding can be beneficial for the application of SiDHN gene in improving crop tolerance to abiotic stress and oxidative damage

Engineered Multifunctional Fluorinated Film Based on Semicontinuous Emulsion Polymerization Using Polymerizable Quaternary Ammonium Emulsifiers

Along with society’s progress, high-quality coatings are widely used. Although fluorinated polymers were successfully prepared by semicontinuous emulsion polymerization with surfactants, chlorotrifluoroethylene (CTFE), and acrylate monomers, the optimization collocation of surfactants still has room for improvement. The traditional emulsifiers are physically absorbed onto the surface of latex particles. The latex film generated by latex particles is unstable in water, which limits its application. Herein, a novel series of cationic quaternary ammonium polymerizable surfactant was selected because it can react with CTFE and acrylate monomers and can become a part of the polymers. We also studied the effects of emulsifier type on resultant emulsion properties. In addition, wonderful weatherability, water resistance, and antibacterial and antifouling of the multifunctional fluorinated films were observed, which would open up a bright future for coating industries

Ratiometric Fluorescence Probe Based on Deep-Red Emissive CdTe Quantum Dots and Eu³⁺ Hybrid for Oxytetracycline Detection

Oxytetracycline (OTC) is an environmental pollutant caused by the abuse of antibiotics, and its content in water is closely related to human health. Therefore, the development of a simple, rapid, and accurate method to detect OTC has become desirable. In this work, a ratiometric fluorescence probe based on deep red emissive CdTe quantum dots (QDs) modified by mercaptopropionic acid and Eu3+ is developed to accurately and rapidly detect OTC in water. After the addition of OTC, the photoluminescence intensity of CdTe QDs at 698 nm remains almost unchanged, while the peak at 617 nm intensifies within 40 s due to the coordination of Eu3+ with OTC. An excellent linear relationship is present between the photoluminescence intensity ratio of I617/I698 and the concentration of OTC. The limit of detection of the probe towards OCT is 5.4 nM. In addition, the probe shows good selectivity and anti-interference ability for OTC in the presence of other antibiotics, including other antibiotics, ions, and amino acids. The probe has been successfully applied to detect OTC in actual samples, demonstrating its potential for environmental application

Bromine Doping as an Efficient Strategy to Reduce the Interfacial Defects in Hybrid Two-Dimensional/Three-Dimensional Stacking Perovskite Solar Cells

Solar-to-electricity conversion efficiency, power conversion efficiency (PCE), and stability are two important aspects of perovskite solar cells (PSCs). However, both aspects are difficult to simultaneously enhance. In the recent two years, two-dimensional (2D)/three-dimensional (3D) stacking structure, designed by covering the 3D perovskite with a thin 2D perovskite capping layer, was reported to be a promising method to achieve both a higher PCE and improved stability simultaneously. However, when reducing the surface defects of 3D perovskite, the thin 2D capping layer itself may probably introduce additional interfacial defects in a 2D/3D stacking structure, which is thought to be able to trigger trap-assisted nonradiative recombination or ion migration. Thus, efforts should be paid to reduce the interfacial defects of 2D hybrid perovskite when serving as a modification layer in a 2D/3D stacking structure PSCs. Here, we demonstrate that bromine (Br) doping of the 2D perovskite capping layer is an efficient strategy to passivate interfacial defects robustly, by which the photoluminescence lifetime is enhanced notably, whereas the interfacial charge recombination is suppressed a lot. As a result, the PCE is enhanced from 18.01% (3D perovskite) to 20.07% (Br-doped 2D/3D perovskite) along with improved moisture stability

Metabolome and transcriptome integration reveals insights into petals coloration mechanism of three species in Sect. Chrysantha chang

Background Sect. Chrysantha Chang, belonging to the Camellia genus, is one of the rare and precious ornamental plants distinguished by a distinctive array of yellow-toned petals. However, the variation mechanisms of petal color in Sect. Chrysantha Chang remains largely unclear. Methods We conducted an integrated analysis of metabolome and transcriptome to reveal petal coloration mechanism in three species, which have different yellow tones petals, including C. chuongtsoensis (CZ, golden yellow), C. achrysantha (ZD, light yellow), and C. parvipetala (XB, milk white). Results A total of 356 flavonoid metabolites were detected, and 295 differential metabolites were screened. The contents of 74 differential metabolites showed an upward trend and 19 metabolites showed a downward trend, among which 11 metabolites were annotated to the KEGG pathway database. We speculated that 10 metabolites were closely related to the deepening of the yellowness. Transcriptome analysis indicated that there were 2,948, 14,018 and 13,366 differentially expressed genes (DEGs) between CZ vs. ZD, CZ vs. XB and ZD vs. XB, respectively. Six key structural genes (CcCHI, CcFLS, CcDFR1, CcDFR2, CcDFR3, and CcCYP75B1) and five candidate transcription factors (MYB22, MYB28, MYB17, EREBP9, and EREBP13) were involved in the regulation of flavonoid metabolites. The findings indicate that flavonoid compounds influence the color intensity of yellow-toned petals in Sect. Chrysantha Chang. Our results provide a new perspective on the molecular mechanisms underlying flower color variation and present potential candidate genes for Camellia breeding