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Phenolic compounds are the predominant chemical constituents in the secondary metabolites of plants and are commonly found in pears. In this study, we focused on the analysis of the phenolic composition and antioxidant activity of leaves from five pear cultivars (Cuiguan, Chaohong, Kuerle, Nanguoli, and Yali) and tea leaves (Fudingdabai as the control) using ultra-performance liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry. The results indicated significant differences in the amount and composition of phenolic metabolites between tea and pear leaves, as well as among the five pear varieties. Only approximately one-third of the metabolites exhibited higher levels in pear leaves compared to that in tea leaves. The total phenol content in the Yali cultivar was higher than that in the other pear cultivars. Furthermore, specific phenolic metabolites with high expression were identified in the leaves of different groups. The levels of delphinidin 3-glucoside, aesculin, prunin, cosmosiin, quercetin 3-galactoside, isorhamnetin-3-O-glucoside, nicotiflorin, narcissin, chlorogenic acid, and cryptochlorogenic acid were relatively high among the five pear cultivars. (-)-Gallocatechin gallate, 6-methylcoumarin, aesculetin, hesperidin, kaempferol, and caftaric acid were identified as specific metabolic substances unique to each type of pear leaf. Most of the differential metabolites showed positive correlations and were primarily enriched in the flavonoid biosynthesis, flavone and flavonol biosynthesis, and phenylpropanoid biosynthesis pathways. DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) analysis indicated that the Yali cultivar exhibited the highest antioxidant activity compared to other varieties. This systematic analysis of the differences in phenolic metabolite composition and antioxidant activity between pear and tea leaves provides a theoretical foundation for the development and utilization of pear leaf resources. [ABSTRACT FROM AUTHOR]

Alluvial fans have been proven to have great utilisation potential in QTP, but to what extent they are suitable for agricultural development is unknown. Therefore, using the alluvial fan in the Lhasa River Basin (LRB) as a case study, this paper established an evaluation system of land suitability for agriculture (LSA). Principal component analysis (PCA) and the exhaustive method (EM) were used to define the minimum dataset (MDS) and then the LSA of the alluvial fan in the LRB was evaluated using a comprehensive index of LSA. Two scientific approaches were implemented to improve the LSA using a scenario simulation. The results showed that the MDS assessed by the EA was more representative compared to the PCA. Alluvial fans with suitable grades are mainly distributed in the Lhasa River's middle and lower reaches. Developing facility agriculture and repairing roads accessing the alluvial fans are effective approaches to improve the LSA, which can increase the suitable-grade area from 58.62% to 97.82% and 63.85%, respectively. Therefore, most alluvial fans in the LRB are suitable for developing agriculture, and under the influence of human activities, there will be more alluvial fans suitable for developing agriculture. Our research provides scientific methods for the sustainable development of land in alpine regions. [ABSTRACT FROM AUTHOR]

The "Qixiadaxiangshui" pear (Pyrus bretschneideri Rehd.1) is a highly valued cultivar known for its crisp texture, abundant juice, and rich aroma. In this study, we reported the first complete chloroplast genome sequence of the "Qixiadaxiangshui" pear, which is 159,885 bp in length with a GC content of 36.58%. The genome exhibits a typical circular quadripartite structure, comprising a large single-copy region (LSC), a small single-copy region (SSC), and a pair of inverted repeat regions (IRs). A total of 131 genes were identified, including 84 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. We also identified 209 simple sequence repeats (SSRs) and several mutation hotspots, such as ndhC-trnM-CAU and trnR-UCU-atpA, which can be applied in molecular identification and phylogenetic studies of Pyrus. Comparative genomic analysis showed high conservation among ten pear cultivars. Phylogenetic analysis indicated that the "Qixiadaxiangshui" pear is closely related to germplasm Dangshansuli, Wonwhang, and Yali, suggesting a recent common ancestor. These findings provided valuable insights into the genetic diversity and evolutionary dynamics of the Pyrus species and contribute to the conservation and breeding of pear germplasm resources. [ABSTRACT FROM AUTHOR]

Coilia nasus is a typical anadromous migratory fish found in the lower reaches of the Yangtze River. Every year, C. nasus clusters offshore and swims upstream along the Yangtze River into the tributaries and lakes in the middle and lower reaches of the Yangtze River to breed. In this study, female C. nasus were collected as study subjects from the Chongming section of Shanghai, the Taizhou section of Jiangsu, and the Anqing section of Anhui. Their ovaries were used to examine tissue sections and investigate gene expression, including the follicle-stimulating hormone receptor (fshr), the luteinizing hormone receptor (lhr), kisspeptin-1 (kiss1), and forkhead box l2 (foxl2), which are related to reproductive development, while the serum levels of estrogen (including estradiol, E2) and progestins (including 17α,20β-dihydroxy-4-pregenen-3-one, 17α,20β-DHP) were also analyzed. Our results showed that, first, the growth period of the oocytes was small in stage II of ovarian development, in which both E2 and 17α,20β-DHP levels and gene expression were low. Then, in stage III, the growth period of the oocytes became large, and the yolk granules and oil droplets began to appear. Simultaneously, E2 and the expression of kiss1 and foxl2 were significantly elevated. Finally, stage IV was the period of a large amount of accumulation of nutrients in the oocytes, and 17α,20β-DHP levels and the expression of fshr and lhr were significantly elevated. These results enrich the theoretical study of ovarian development in the natural population of C. nasus, supplementing the biological basis of C. nasus reproduction and scientifically supporting the study of C. nasus population ecology and resource conservation. [ABSTRACT FROM AUTHOR]

Photocatalytic NO removal is usually accompanied by the generation of NO2, an intermediate with a higher toxicity than NO. Therefore, it is critically important to develop new photocatalysts capable of NO selective conversion. Herein, we report on the synergistic roles of cyano and hydroxyl functional groups in photocatalytic NO removal. According to the results, the NO2 production efficiencies on cyano/hydroxyl-group-modified g-C3N4 (DCN-O-R) was limited to 4.8%, which was lower than that of cyano-group-modified g-C3N4 (DCN, 38.6%) and pure g-C3N4 (CN, 50.0%). Meanwhile, the photocatalytic NO conversion efficiency over DCN-O-R was higher than that of DCN and g-C3N4. It was found that the insertion of cyano groups favorably changes the energy band of g-C3N4 towards the generation of •O2−. NO can only be oxidized to NO2 by the photogenerated holes. When NO2 is adsorbed on the surface of hydroxyl groups, it can be further oxidized to the product NO3− by •O2−. The synergistic effect of bifunctional groups regulates the conversion pathway from NO→NO2 to NO→NO2→NO3−. This work provides a strategy to abate toxic intermediates during the NO removal process, underlining the importance of surface/interface molecular engineering in regulating catalytic reaction pathways. [ABSTRACT FROM AUTHOR]