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Poly(9,9-di-n-octylfluorene) (PFO) is a promising material for polymer light-emitting diodes (PLEDs) due to its advantageous properties. To enhance its electron transporting capabilities, diblock polymers were synthesized by attaching polystyrene (PSt) chains of varying lengths to one end of the PFO molecule. In a comparative study with PFO homopolymer, the diblock polymers maintained similar thermal properties, absorption spectra, and photoluminescent stability, while exhibiting slightly deeper lowest unoccupied molecular orbital (LUMO) levels and higher crystallinity. Notably, diblock polymers with shorter polystyrene blocks demonstrated higher electron mobility than the PFO homopolymer and diblock polymers with excessively long polystyrene blocks. These findings suggest that the optimal chain length of the polystyrene block is crucial for maximizing electron mobility, thus offering valuable insights for designing high-performance PLED materials. [ABSTRACT FROM AUTHOR]

Objective To analyze the effects and molecular mechanisms of AhR signaling pathway in the treatment of scleroderma with Bushen Yijing Decoction. Methods The active ingredients of Bushen Yijing Decoction and its target genes, AhR signaling pathway genes and the genes related to scleroderma were searched through TCMSP and other databases, and LC-MS results. Target gene network diagram of scleroderma, AhR pathway and the key active ingredients in Bushen Yijing Decoction were constructed. The protein-protein interaction network was constructed with STRING database, and GO and Genome KEGG were also performed. Finally, the molecular docking of the active ingredients and AhR were verified. Results Ferulic acid, quercetin, kaempferol, isoferulic acid and luteolin were key active ingredients in Bushen Yijing Decoction for the treatment of scleroderma by targeting AhR signaling pathway. These active ingredients possibly regulated AhR signaling pathway molecules, including IL-6, CTNNB1, HSP90AA1, TNF and PTGS2, which were involved in the pathogenesis of scleroderma. Molecular docking showed that the binding energies of ferulic acid, kaempferol, quercetin, isoferulic acid and luteolin with AhR were lower than -6. 0 kcal/mol, indicating a good binding activity. Conclusions The mechanisms by which Bushen Yijing Decoction treats scleroderma can be attributed to the active ingredients such as ferulic acid, quercetin, kaempferol, isoferulic acid, luteolin, which target AhR signaling pathway and regulate core targets, including IL-6, CTNNB1, HSP90AA1, TNF and PTGS2. [ABSTRACT FROM AUTHOR]

Most of plants uptook NO3--N faster at the low pH 4.0 than at pH 6.0 and uptook NH4+-N slower, but few experimental plants showed different tendency. The exceptions probably due to excessive nitrate outflux of some maize and wheat varieties (Suyu 19. Zhendan958 and Yangmai12) at low pH. Some other experimental plants (Huaidao 8. Nongda108 and Yangmai12) even show no obvious NH4+ toxic symptoms at pH 4.0. The effect of low pH on uptake rate of NH4+-N and NO3--N varied with plant species, varieties, and the difference increased with the growth age of seedlings.

Nitrate uptake characteristics and ammonium effects were compared between upland rice (Brazilian upland rice) and paddy rice (Wuyujing 3 and Yangdao 6) through the glass microelectrode technique and the concentration gradient method of uptake kinetics. Results indicated that nitrate uptake by rice seedlings and ammonium effects were related to transmembrane potential difference, and upland rice and paddy rice presented obviously different responses. Nitrate induced a rapid depolarization and then a slow repolarization of transmembrane potential in root epidermal cells, and even hyperpolarization was observed when nitrate concentration was low. Resting transmembrane potential of epidermal cells in Brazilian upland rice roots was lower and its response to NO3- was bigger than that of two paddy rice species. Depolarization of membrane potential was amplified when ammonium was simultaneously added with nitrate into the measure medium, but repolarization was reduced, even disappeared. Brazilian upland rice seedlings had high Vmax of nitrate uptake and low Km, furthermore, Vmax and Km were little affected by ammonium, but Vmax of Wuyujing 3 was reduced significantly. Therefore, inhibition of ammonium to nitrate uptake possibly due to decrease of membrane potential and influence of nitrate transporters. Moreover, inhibition of NH4+ differed obviously between upland rice and paddy rice.

Nitrification in the rhizosphere is a crucial process in controlling nitrogen‐use efficiency (NUE) in flooded paddy soils. To understand the relationship between the nitrification ability of the rhizosphere and NUE, pot experiments using 15N tracer technique were conducted to investigate the impacts of the rhizosphere soil net nitrification rate on NUE and denitrification losses at different rice growth stages in two paddy soils, which were sampled from Jurong (JR) and Yancheng (YC) in Jiangsu Province in China. The results showed that the nitrification rate in JR rhizosphere soil was lower than in YC rhizosphere soil at all rice growth stages. The abundance of ammonia‐oxidizing bacteria (AOB), ammonia‐oxidizing archaea (AOA), and pH in YC rhizosphere soils were always higher than in JR rhizosphere soils. Rice yield, biomass, NUE, leaf glutamine synthetase (GS) activity, and nitrate reductase (NR) activity were higher in JR soils with low nitrification rates than in YC soils with high nitrification rates (p < 0.05). In contrast, denitrification loss from JR soil (12.69%–23.41%) was lower than that from YC soil (26.83%–40.98%; p < 0.05) for each rice growth stage. The biomass and NUE decreased significantly as the net nitrification rate, the abundance of AOA and AOB of both the JR and YC rhizosphere soils increased (p < 0.05), and the denitrification loss was enhanced as the rhizosphere nitrification rate increased in the JR and YC soils (p < 0.05) during the rice growth period. The rhizosphere‐dominant AOB community Nitrosospira is the key factor affecting the nitrification rate and then decreasing rice NUE. In general, the rhizosphere nitrification rate in paddy soils is a primary factor controlling the rice NUE and denitrification loss. [ABSTRACT FROM AUTHOR]

The coastal saline-alkali soil in eastern China is an important reserve arable land resource. Adding exogenous organic material is an effective way to improve soil fertility and promote the conversion of saline-alkali soil to agricultural soil. In this study, a field plot experiment was used to investigate the influences of different organic materials (vinegar residue, VR; sewage sludge, SS; vermicompost, VC) on the reduction in salinity-alkalinity barrier factors, the accumulation of soil organic carbon (SOC), and the improvement in soil fertility in saline-alkali soil. The results indicated that applying different types of exogenous organic materials reduced soil electrical conductivity (EC) and pH, promoted SOC accumulation, and increased the barley yield. With the same application rate, VR application was more beneficial in reducing soil EC and pH, accumulating SOC, and increasing barley yield compared to SS and VC applications. In particular, the barley yield with VR application was higher than that with SS and VC applications by 18.4% and 26.6% on average, respectively, during the two-year experiment. Correlation and path analysis revealed that the barley yield was significantly negatively correlated with soil barrier factors (EC and pH), but EC in SS and VC-treated soils had an indirect negative effect on barley yield, while EC in VR-treated soil had a direct negative effect (−2.24). In addition, the direct (−4.46) and indirect (5.39) contributions of SOC to barley yield were higher with VR than those with SS and VC, while the direct contribution of soil aggregate to barley yield was lower with VR than that with SS and VC. Therefore, compared with SS and VC applications, VR application led to a fast reduction in soil barrier factors and the rapid accumulation of SOC, which were more beneficial for increasing barley yields in saline-alkali soil. [ABSTRACT FROM AUTHOR]