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Rat limbal niche cells (LNCs) have been proven to induce transdifferentiation of oral mucosal epithelial cells (OMECs) into corneal epithelial-like cells termed transdifferentiated oral mucosal epithelial cells (T-OMECs). This investigation aimed to evaluate the effect of subconjunctival T-OMEC injections on alkali-induced limbal stem cell deficiency (LSCD) in rats. LNCs were cocultured with OMECs in the Transwell system to obtain T-OMECs, with NIH-3T3 cells serving as a control. Subconjunctival injection of single T-OMEC or OMEC suspension was performed immediately after corneal alkali injury. T-OMECs were prelabeled with the fluorescent dye CM-DiI in vitro and tracked in vivo. Corneal epithelial defect, opacity, and neovascularization were quantitatively analyzed. The degree of corneal epithelial defect (from day 1 onward), opacity (from day 5 onward), and neovascularization (from day 2 onward) was significantly less in the T-OMEC group than in the OMEC group. Cytokeratin 12 (CK12), pigment epithelium–derived factor, and soluble fms-like tyrosine kinase-1 were expressed at a higher rate following T-OMEC injection. Some CM-DiI-labeled cells were found to be coexpressed with CK12, Pax6, and ΔNp63α in the corneal epithelium after subconjunctival injection. Subconjunctival injection of T-OMECs prevents conjunctival invasion and maintains a normal corneal phenotype, which might be a novel strategy in the treatment of LSCD: [ABSTRACT FROM AUTHOR]

Currently, the aquatic environment of the Tuojiang River basin in Sichuan Province is severely polluted by non-point sources of total nitrogen (TN). This study adopts the pollution discharge coefficient method to estimate the TN pollution load of non-point sources in this watershed during 2007-2017. The temporal and spatial distribution and transfer trends of the TN pollution load in the Tuojiang River basin were examined, based on center-of-gravity statistical and spatial analysis technology. This study aimed to provide an accurate theoretical basis for the prevention and early identification of non-point source pollution in the Tuojiang River basin. The results indicate that livestock breeding was the main non-point source of TN pollution and contributed more than 45% to the TN pollution load during 2007-2017. The contribution rate of rural life and domestic waste decreased continually during the study period, whereas that of farmland solid waste and farmland runoff exhibited an increasing trend. The total pollution load of TN exhibited a decreasing trend during 2007-2017. The maximum and minimum TN pollution loads occurred in 2010 and 2017 with values of 5.7×10 4 t and 4.69×10 4 t, respectively. Spatial heterogeneity of the pollution load, together with the uneven distribution of rainfall runoff, caused a shift from northwest to southeast in the pollution-load centers of gravity for livestock and poultry breeding, farmland solid waste, and farmland runoff. Southeast of the watershed is the key area for prevention and control of these pollution sources. A shift in the centers of gravity for rural living and household waste pollution, from southeast to northwest, was attributed to agricultural populations transforming to urban populations in the southeastern counties. The maximum transfer range was 66.35 km 2 , and this minimum boundary circle is the key identification area of pollution source pollution load change. Northwest of Tuojiang River basin is the key area in which TN pollution from rural living and rural household waste can be prevented. This research expands the methods for exploring the temporal and spatial evolution of pollution load in the Tuojiang River basin, which is of great significance for improving the aquatic environment and promoting sustainable development of the basin economy.

A copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3'-disubstituted oxindoles is developed. Tandem C-H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3'-disubstituted oxindoles in moderate to good yields.