Long-Term Thermal Stability of Ionic Surfactants for Improving Oil Production at High-Salinity High-Temperature Conditions.

Surfactants with stable chemical structures and robust ability are required to lower interfacial tension and stabilize emulsions for successful chemical injection applications. This work selected six surfactants, dodecyl carboxylic sodium (LAS), dodecyl sulfonate dodecyl sodium (SLS), dodecyl sulfate sodium (SDS), dodecyltrimethylammonium bromide (DTAB), 3-(N,N-dimethylmyristylammonio) propanesulfonate (SB3-14) and a sulfobetaine formulation (PCT-10), and systematically investigated the ionic-type effects on thermal stability at 95 °C for 150 days in high-salinity water (total dissolved solids (TDS) = 57,600 ppm). With characterizations of aged samples performed through a spinning drop tensiometer, high-performance liquid chromatography, and infrared spectroscopy, it can be seen that the long-term stability sequence of ionic surfactants in solutions is sulfobetaine ≈ quaternary ammonium > sulfonate > sulfate > carboxylate. The carboxylate possibly precipitates out from the solution in the acid form, and the sulfonate and sulfate decompositions are due to the hydrolysis of the anionic head, forming alcohol and NaHSO3/NaHSO4. Obvious decomposition of sulfobetaine and quaternary ammonium was not observed, but these molecules might suffer the elimination of the ionic head, forming the corresponding alkene and amine. The results also show that the dissolved oxygen in the solution preparation significantly sped up the degradation of sulfonates. At last, the emulsion stability tests of crude oil in surfactant solutions showed that sulfobetaine surfactants retained the highest emulsifying ability after thermal aging and thus are promising candidates for long-term chemical injection in high-temperature high-salinity reservoirs.

A telomere-to-telomere gap-free reference genome assembly of avocado provides useful resources for identifying genes related to fatty acid biosynthesis and disease resistance.

Avocado (Persea americana Mill.) is an economically valuable plant because of the high fatty acid content and unique flavor of its fruits. Its fatty acid content, especially the relatively high unsaturated fatty acid content, provides significant health benefits. We herein present a telomere-to-telomere gapless genome assembly (841.6 Mb) of West Indian avocado. The genome contains 40 629 predicted protein-coding genes. Repeat sequences account for 57.9% of the genome. Notably, all telomeres, centromeres, and a nucleolar organizing region are included in this genome. Fragments from these three regions were observed via fluorescence in situ hybridization. We identified 376 potential disease resistance-related nucleotide-binding leucine-rich repeat genes. These genes, which are typically clustered on chromosomes, may be derived from gene duplication events. Five NLR genes (Pa11g0262, Pa02g4855, Pa07g3139, Pa07g0383, and Pa02g3196) were highly expressed in leaves, stems, and fruits, indicating they may be involved in avocado disease responses in multiple tissues. We also identified 128 genes associated with fatty acid biosynthesis and analyzed their expression patterns in leaves, stems, and fruits. Pa02g0113, which encodes one of 11 stearoyl-acyl carrier protein desaturases mediating C18 unsaturated fatty acid synthesis, was more highly expressed in the leaves than in the stems and fruits. These findings provide valuable insights that enhance our understanding of fatty acid biosynthesis in avocado.

[M2 macrophages inhibit CD8+ T cells and facilitate the malignant biological behavior of esophageal cancer cells].

Objective To explore the impact of M2 macrophages on the malignant biological behavior of esophageal cancer by inhibiting the anti-tumor ability of CD8+ T cells. Methods Using phorbol myristate acetate (PMA) combined with interleukin 4 (IL-4)/IL-13, we induced human monocytic leukemia cells (THP-1) to become M2 macrophages and the detected related inflammatory factors by real-time quantitative PCR. We used magnetic bead sorting to isolate CD8+ T cells from healthy volunteers' peripheral blood, and verified the purity of the sorted cells by flow cytometry. We established a non-contact co-culture system between CD8+ T cells and esophageal squamous carcinoma cells (CD8+ T cell), and established a non-contact co-culture system between M2 macrophages, CD8+ T cells, and esophageal squamous carcinoma cells (M2 macrophages combined with CD8+ T cell). The plate clone formation assay and CCK-8 cell toxicity assay were used to detect the proliferation ability of tumor cells in each group. The TranswellTM assay was used to detect the invasive and migratory abilities of tumor cells in each group. Flow cytometry was used to detect and analyze the apoptosis of tumor cells in each group. GraphPadPrism9.5 software was used for statistical analysis and graphing. Results After induction, the expression of IL-10 and arginase 1 (Arg1) in macrophages was upregulated, while the expression of IL-12 and tumor necrosis factor-alpha (TNF-α) was downregulated, showing the characteristics of M2 macrophages. Peripheral blood CD8+ T cells were successfully selected by magnetic bead sorting, with a positive rate of over 90%. The proliferation, invasion, migration and anti-apoptosis ability of esophageal squamous carcinoma cells co-cultured with CD8+ T cells in the non-contact manner were significantly lower than those of the single cancer cell group; while the proliferation, invasion, migration and the anti-apoptosis ability of esophageal squamous carcinoma cells co-cultured with CD8+ T cells pretreated with M2 macrophage conditioned medium were significantly enhanced compared with those of esophageal squamous carcinoma and CD8+ T cells co-cultured group. Conclusion M2 macrophages promote the proliferation, invasion, migration, and anti-apoptosis of esophageal cancer cells by inhibiting the anti-tumor ability of CD8+ T cells.

Si Doping Enables Activity and Stability Enhancement on Atomically Dispersed Fe-Nx /C Electrocatalysts for Oxygen Reduction in Acid.

Fe-N-C represents the most promising non-precious metal catalysts (NPMCs) for the oxygen reduction reaction (ORR) in fuel cells, but often suffers from poor stability in acid due to the dissolution of metal sites and the poor oxidation resistance of carbon substrates. In this work, silicon-doped iron-nitrogen-carbon (Si/Fe-N-C) catalysts were developed by in situ silicon doping and metal-polymer coordination. It was found that Si doping could not only promote the density of Fe-Nx /C active sites but also elevated the content of graphitic carbon through catalytic graphitization. The best-performing Si/Fe-N-C exhibited a half-wave potential of 0.817 V vs. reversible hydrogen electrode in 0.5 m H2 SO4 , outperforming that of undoped Fe-N-C and most of the reported Fe-N-C catalysts. It also exhibited significantly enhanced stability at elevated temperature (≥60 °C). This work provides a new way to develop non-precious metal ORR catalysts with improved activity and stability in acidic media.