Custom-designed nucleases afford a powerful reverse genetic tool for direct gene disruption and genome modification in vivo. Among various applications of the nucleases, homologous recombination ...(HR)-mediated genome editing is particularly useful for inserting heterologous DNA fragments, such as GFP, into a specific genomic locus in a sequence-specific fashion. However, precise HR-mediated genome editing is still technically challenging in zebrafish. Here, we establish a GFP reporter system for measuring the frequency of HR events in live zebrafish embryos. By co-injecting a TALE nuclease and GFP reporter targeting constructs with homology arms of different size, we defined the length of homology arms that increases the recombination efficiency. In addition, we found that the configuration of the targeting construct can be a crucial parameter in determining the efficiency of HR-mediated genome engineering. Implementing these modifications improved the efficiency of zebrafish knock-in generation, with over 10% of the injected F0 animals transmitting gene-targeting events through their germline. We generated two HR-mediated insertion alleles of sox2 and gfap loci that express either superfolder GFP (sfGFP) or tandem dimeric Tomato (tdTomato) in a spatiotemporal pattern that mirrors the endogenous loci. This efficient strategy provides new opportunities not only to monitor expression of endogenous genes and proteins and follow specific cell types in vivo, but it also paves the way for other sophisticated genetic manipulations of the zebrafish genome.
How astrocytes grow and integrate into neural circuits remains poorly defined. Zebrafish are well suited for such investigations, but bona fide astrocytes have not been described in this system. Here ...we characterize a zebrafish cell type that is remarkably similar to mammalian astrocytes that derive from radial glial cells and elaborate processes to establish their territories at early larval stages. Zebrafish astrocytes associate closely with synapses, tile with one another and express markers, including Glast and glutamine synthetase. Once integrated into circuits, they exhibit whole-cell and microdomain Ca
transients, which are sensitive to norepinephrine. Finally, using a cell-specific CRISPR-Cas9 approach, we demonstrate that fgfr3 and fgfr4 are required for vertebrate astrocyte morphogenesis. This work provides the first visualization of astrocyte morphogenesis from stem cell to post-mitotic astrocyte in vivo, identifies a role for Fgf receptors in vertebrate astrocytes and establishes zebrafish as a valuable new model system to study astrocyte biology in vivo.
In this research, titanium slag (TS) was used as an alternative aggregate to prepare reactive powder concrete (RPC). The mechanical properties, hydration characteristics, and interface structure of ...the RPC was investigated. The results showed that the porous, low-activity TS aggregate had high water adsorption and proper secondary hydration during moulding and hardening. This accelerated the early-age hydration reaction of RPC and significantly improved the interfacial structure between paste and aggregate. Ca2+, Mg2+, and Si4+ present in TS leached out and generated additional C-S-H around the aggregate during hydration, which filled the gap between paste and aggregate
Exploring the ratio of metal centers to organic ligands and the amount of DMF are important to improve the stability and adsorption efficiency of MOF materials as adsorbents. In this work, ...MIL101(Fe)-Na2CO3 was successfully obtained by modification with formic acid, sodium carbonate, carbon nanotubes, and moieties. The adsorption efficiency of MIL-101(Fe) on Cr(VI) was greatly improved, and the removal efficiency was able to reach 100% in 20 min with a maximum adsorption capacity of 20 mg/g. The inhibition order of the competing anions for the removal of hexavalent chromium was as follows: Cl− < NO3− < SO42−. The analysis of the adsorption thermodynamic model found that the adsorption of MIL101(Fe)-Na2CO3 for Cr(VI) showed spontaneous heat-absorbing and entropy-increasing chemisorption behavior. When using NaOH as the eluent and HCl as the regeneration stabilizer, MIL-101(Fe)-Na2CO3 had good adsorption capacity in multiple cycles.
To improve the out-of-plane collaborative performance of timber frames and walls, a metal connector is proposed and designed. A finite element model of the wall is established, and the composite ...block damage criteria and surface contact behavior are validated. Additionally, one group without metal connectors and three groups with different numbers of metal connectors placed at various positions in traditional residential wall models are established. Using static loading simulation, the influence of different numbers of metal connectors on the out-of-plane damage patterns, deformation characteristics, and shear force distribution is analyzed. The study reveals that top metal connectors significantly reduce the out-of-plane displacement of the top wall by up to 84.6%. Metal connectors have a significant impact on the deformation capacity of brick walls, with a maximum enhancement of 65.3%. The metal connectors in the middle and lower parts transfer the wall loads to the columns, increasing the horizontal shear at the column head by approximately 7%. The connectors in the middle and lower parts effectively improve the collaborative performance of brick walls and wooden frames.
The age of onset of sexual maturity is an important reproductive trait in chickens. In this study, we explored candidate genes associated with sexual maturity and ovary development in chickens. We ...performed DGE RNA-sequencing analyses of ovaries of pre-laying (P-F-O1, L-F-O1) and laying (P-F-O2, L-F-O2) hens of two sub-breeds of Ningdu Yellow chicken. A total of 3197 genes were identified in the two comparisons, and 966 and 1860 genes were detected exclusively in comparisons of P-F-O1 vs. P-F-O2 and L-F-O1 vs. L-F-O2, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that genes involved in transmembrane signaling receptor activity, cell adhesion, developmental processes, the neuroactive ligand-receptor interaction pathway, and the calcium signaling pathway were enriched in both comparisons. Genes on these pathways, including growth hormone (
), integrin subunit beta 3 (
), thyroid stimulating hormone subunit beta (
), prolactin (
), and transforming growth factor beta 3 (
), play indispensable roles in sexual maturity. As a gene unique to poultry, hen egg protein 21 kDa (
) was chosen as the candidate gene. Differential expression and association analyses were performed. RNA-seq data and qPCR showed that
was significantly differentially expressed in pre-pubertal and pubertal ovaries. A total of 23 variations were detected in
. Association analyses of single nucleotide polymorphisms (SNPs) in
and reproductive traits showed that rs315156783 was significantly related to comb height at 84 and 91 days. These results indicate that
is a candidate gene for sexual maturity in chickens. Our results contribute to a more comprehensive understanding of sexual maturity and reproduction in chickens.
•Nano-ZnO delayed the early-age hydration of CZ but had little effect on its later compressive strength.•Nano-ZnO coarsened the pore size and decreased the autogenous shrinkage of CZ.•Formation and ...disintegration of Zn(OH)2 on surface of clinker particle controlled the CZ hydration.
Nano-ZnO could delay the setting and the hardening of cement pastes but promote the later cement hydration, which made it an ideal inorganic retarder in cement based materials. In this research, properties and structures of fresh and hardened cement pastes containing nano-ZnO (CZ) were tested. Early hydration of CZ was greatly delayed and its early mechanical performances were decreased. However, the 28 days compressive strength of CZ with 0.1 wt% nano-ZnO was slightly higher than that of blank paste. Nano-ZnO was rapidly dissolved in alkaline environment to form the amorphous Zn(OH)2 in the early hydration stage, the deposition of Zn(OH)2 layer on the surface of clinker particles would block the early hydration. With the processing of cement hydration, as-formed Zn(OH)2 would be further reacted with Ca(OH)2 to generate intermediate Ca(Zn(OH)3)2·2H2O, which broke the Zn(OH)2 coatings and promoted the cement hydration in this period. In addition, the coarsening of capillary pores ranged from 5 nm to 50 nm in hardened CZ matrix was observed, which was presumed to be responsible for the autogenous shrinkage reduction of CZ pastes.
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•Furnace temperature field estimation based on FLIC simulation and data-driven model.•Multi-conditions design based on micro, composition, and operating parameters.•Multi-dimensional ...visual analysis of incinerator virtual temperature field.•Temperature field model by using deep ensemble forest with potential interpretability.
The furnace temperature field is key information to reflect the combustion conditions and is related to process safety, equipment failure rates, and pollution emissions in municipal solid waste incinerators. However, the measurement of the actual temperature distribution of the incinerator is difficult because of the limitations of physical sensors (thermocouples). A new furnace temperature field modeling strategy was proposed to address the above problem. It included five virtual temperature points, with the numerical simulation and the deep forest regression algorithm used. First, numerical models of different benchmark conditions were established via FLIC. Second, modeling data were obtained by orthogonal experiments. Third, deep forest regression based on the fully connected cross layer (DFR-clfc) was used to establish five virtual temperature models. The five models had high prediction performance (R2 = 0.707, 0.870, 0.918, 0.895, and 0.907) and characterized the distribution of the furnace temperature. The grate speed had the greatest influence on temperature distribution, and based line condition (2) was more suitable for a stable operation. The novelties of the work are as follows. (1) Furnace temperature field estimation based on FLIC simulation and data-driven model. (2) Multi-conditions design based on micro, composition, and operating parameters. (3) Multi-dimensional visual analysis of incinerator virtual temperature field. (4) Temperature field model by using deep ensemble forest with potential interpretability.
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