43 research outputs found
Generation of integration-free neural progenitor cells from cells in human urine
Human neural stem cells hold great promise for research and therapy in neural disease. We describe the generation of integration-free and expandable human neural progenitor cells (NPCs). We combined an episomal system to deliver reprogramming factors with a chemically defined culture medium to reprogram epithelial-like cells from human urine into NPCs (hUiNPCs). These transgene-free hUiNPCs can self-renew and can differentiate into multiple functional neuronal subtypes and glial cells in vitro. Although functional in vivo analysis is still needed, we report that the cells survive and differentiate upon transplant into newborn rat brain.postprin
Seismic Response Analysis of SteelâConcrete Composite Frame Structures with URSP Connectors
The uplift-restricted and slip-permitted (URSP) connector is a new type of connector used in steelâconcrete composite structures that has been proven to improve the structural performance of negative moment regions. Since this connector changes the interface restraint between the slab and steel beam, there is an imperative to study the seismic performance of steelâconcrete composite frame systems with this new type of connector. In this study, the dynamic behavior of composite frame structures with URSP connectors under seismic loads was numerically investigated. First, a beamâshell mixed model was used and complex interfaces of different connectors were considered while establishing a numerical model to conduct elastoâplastic time history analysis under various seismic loads. This numerical model was validated with the frame sub-assemblage experimental results of quasi-static cyclic tests. Second, the model analysis results of structures with URSP connectors were obtained and compared with those of traditional structures. Third, dynamic response results including roof displacement, inter-story displacement, and the distribution and failure modes of plastic hinges were analyzed and compared. The comparisons indicated that the arrangement of full-span URSP connectors had a non-negligible influence on the dynamic behavior of the systems. The arrangement increased the maximum inter-story displacement by 31.5% and induced adverse effects in certain cases, which is not suggested in the application of URSP connectors. The partial arrangement of URSP connectors had little influence on the dynamic behavior of the systems, and the frame systems still showed a good seismic performance, which was the same as the traditional composite structural system. These findings may promote the application of URSP connectors in composite structures
Eco-Innovation : Corn Stover as the Biomaterial in Packaging Designs
Shandong, Chinaâs largest agricultural province, generates a massive amount of agricultural waste each year, with corn stover being the predominant type. Although current agricultural waste management primarily involves sustainable practices carried out by professional companies, this study seeks to explore a simpler, more accessible method of handling stover waste. Guided by positivist theory and several experiments, a formula was developed, primarily composed of corn stover powder and natural substances such as glycerin. In this process, we designed and implemented four control experimental groups with water as the quantity used to investigate the influence of different material content in the formula. The resultant material was then subjected to property analyses, including tests on colouration, toughness, etc. Ultimately, the material was applied in a small-scale test as a raw material for an agricultural product packaging design. The study, rooted in sustainability, environmental protection, and the establishment of a local circular economy, fills the gap in current research of lacking design knowledge interventions
Photo-orientation of liquid crystals due to light-induced desorption and adsorption of dye molecules on an aligning surface
none8siWe show that adsorption of dye molecules control the light-induced alignment of dye-doped nematic liquid crystal (LC) on a nonphotosensitive polymer surface. The dependencies of light-induced twist structures on exposure, thermal baking, thickness, and aging before irradiation of the LC cells allowed us to propose the following mechanism for the alignment. Before irradiation, the "dark"-adsorbed layer on the tested surface is formed from dye molecules predominantly aligned along the initial direction of the director. Irradiation of the cell with linearly polarized light produces an additional layer with different orientational ordering of dye molecules. The final easy axis is determined by the competition of "dark" and light-induced contributions to anchoring and is aligned between the "dark" easy axes and polarization of the light. For quantitative interpretation, we apply the tensor model of anchoring and assume that the photoalignment in the mesophase is a cumulative effect of the light-induced anchoring on the background of the already existing anisotropic "dark" dye layer.E. OUSKOVA; YU. REZNIKOV; S.V. SHIYANOVSKII; L. SU; J.L. WEST; O.V. KUKSENOK; O. FRANCESCANGELI; F. SIMONIE., Ouskova; Reznikov, Y. U.; S. V., Shiyanovskii; L., Su; J. L., West; O. V., Kuksenok; Francescangeli, Oriano; Simoni, Francesc
Tetraphenylethylene-doped covalent organic frameworks as a highly efficient aggregation-induced electrochemiluminescence emitter for ultrasensitive miRNA-21 analysis
MicroRNAs (miRNAs) as a well-known kind of cancer marker are closely associated with the formation and metastasis of tumors. Here, a novel tetraphenylethylene (TPE)-doped covalent organic frameworks (TPE-COFs) with strong aggregation-induced electrochemiluminescence (AIECL) response was synthesized and introduced to construct an ultrasensitive biosensor for the detection of miRNA-21. The strong aggregation-induced emission (AIE) response was obtained because the molecular motion of TPE was restricted by COFs which had the porosity and highly ordered topological structure. Meanwhile, the porous structure of COFs allowed TPE to react with electrochemiluminescence (ECL) coreactants more effectively. Furthermore, COFs significantly improved the electron transport efficiency of the entire ECL system. All of these endowed the TPE-COFs with superior AIECL performance. Then, a TPE-COFs based ECL resonance energy transfer (ECL-RET) system was constructed for ultrasensitive miRNA-21 biosensing with differential signal readout. The proposed assays exhibited excellent sensitivity with a wide dynamic range from 10 aM to 1Â pM and a low detection limit of 2.18 aM. Therefore, these indicated that doping TPE in COFs was a creative way to develop functional COFs and provided an effective way for enhancing AIECL. Furthermore, this work boarded the application of AIECL in analytical chemistry
MADS-box Transcription Factor OsMADS25 Regulates Root Development through Affection of Nitrate Accumulation in Rice
MADS-box transcription factors are vital regulators participating in plant growth and development process and the functions of most of them are still unknown. ANR1 was reported to play a key role in controlling lateral root development through nitrate signal in Arabidopsis. OsMADS25 is one of five ANR1-like genes in Oryza Sativa and belongs to the ANR1 clade. Here we have investigated the role of OsMADS25 in the plantâs responses to external nitrate in Oryza Sativa. Our results showed that OsMADS25 protein was found in the nucleus as well as in the cytoplasm. Over-expression of OsMADS25 significantly promoted lateral and primary root growth as well as shoot growth in a nitrate-dependent manner in Arabidopsis. OsMADS25 overexpression in transgenic rice resulted in significantly increased primary root length, lateral root number, lateral root length and shoot fresh weight in the presence of nitrate. Down-regulation of OsMADS25 in transgenic rice exhibited significantly reduced shoot and root growth in the presence of nitrate. Furthermore, over-expression of OsMADS25 in transgenic rice promoted nitrate accumulation and significantly increased the expressions of nitrate transporter genes at high rates of nitrate supply while down-regulation of OsMADS25 produced the opposite effect. Taken together, our findings suggest that OsMADS25 is a positive regulator control lateral and primary root development in rice
Discovery and structure-activity relationship studies of novel tetrahydro-β-carboline derivatives as apoptosis initiators for treating bacterial infections
Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety. In this paper, to discover the new bactericide candidates, we designed, prepared a new type of 1,2,3,4-tetrahydro-β-carboline (THC) derivatives and evaluated the in vitro and in vivo bioactivities against the Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac), and Pseudomonas syringae pv. actinidiae (Psa). The in vitro bioassay results exhibited that most title molecules possessed good activity toward the three plant pathogenic bacteria, the compound A17 showed the most active against Xoo and Xac with EC50 values of 7.27 and 4.89 mg mLâ1 respectively, and compound A8 exhibited the best inhibitory activity against Psa with EC50 value of 4.87 mg mLâ1. Pot experiments showed that compound A17 exhibited excellent in vivo antibacterial activities to manage rice bacterial leaf blight and citrus bacterial canker, with protective efficiencies of 52.67 and 79.79% at 200 mg mLâ1, respectively. Meanwhile, compound A8 showed good control efficiency (84.31%) against kiwifruit bacterial canker at 200 mg mLâ1. Antibacterial mechanism suggested that these compounds could interfere with the balance of the redox system, damage the cell membrane, and induce the apoptosis of Xoo cells. Taken together, our study revealed that tetrahydro-β-carboline derivatives could be a promising candidate model for novel broad-spectrum bactericides