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To investigate the function and possible mechanism of miR-92a in malignant behaviors such as paclitaxel resistance in ovarian cancer (OC) cells. The miR-92a and PTEN expression were detected by real-time PCR (RT-PCR). The cell viability and apoptosis were detected by MTT, colony formation and flow cytometry assay, respectively. Dual-luciferase reporter assay was adopted to verify the targeting relationship between miR-92a and PTEN. Besides, we measured the relative protein levels of PTEN and p-AKT/AKT by Western blot. MiR-92a was significantly highly expressed in OC cells, and its high expression could notably enhance paclitaxel resistance, cell proliferation and colony formation, as well as inhibit apoptosis in SKOV3-Tax cells. Further luciferase reporter assay and expression detection showed that miR-92a could target and regulate PTEN and that there was a targeted relationship between them. In addition, further exploration of the mechanism revealed that miR-92a regulated PTEN/Akt signaling pathway. MiR-92a not only promotes the proliferation, colony formation and paclitaxel resistance of SKOV3-Tax cells in OC, but also inhibits apoptosis, and it may be related to the regulation of the PTEN/Akt signaling pathway. MiR-92a serves as a potential biomarker for the malignant biological behavior of OC cells.

In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria.

To investigate different contents of pu-erh tea polyphenol affected by abiotic stress, this research determined the contents of tea polyphenol in teas produced by Yuecheng, a Xishuangbanna-based tea producer in Yunnan Province. The study drew a preliminary conclusion that eight factors, namely, altitude, nickel, available cadmium, organic matter, N, P, K, and alkaline hydrolysis nitrogen, had a considerable influence on tea polyphenol content with a combined analysis of specific altitudes and soil composition. The nomogram model constructed with three variables, altitude, organic matter, and P, screened by LASSO regression showed that the AUC of the training group and the validation group were respectively 0.839 and 0.750, and calibration curves were consistent. A visualized prediction system for the content of pu-erh tea polyphenol based on the nomogram model was developed and its accuracy rate, supported by measured data, reached 80.95%. This research explored the change of tea polyphenol content under abiotic stress, laying a solid foundation for further predictions for and studies on the quality of pu-erh tea and providing some theoretical scientific basis.

Lightning rods have been developed to prevent damage caused by lightning to organisms. However, the biological effect of the current transmitted into the soil through lightning rods is unknown. In this study, we analyzed the effects of lightning on soil properties, the microbial community, and the active components of Pu-erh tea (Camellia sinensis var. assamica) near lightning rods. The results showed that the contents of organic matter and available potassium, copper, and calcium in rhizosphere soil near the lightning rod were significantly higher than those in control soil (P < 0.05), while the contents of total potassium, phosphorus, iron, magnesium, and aluminum decreased. Lightning significantly increased the bacterial diversity of Pu-erh rhizosphere soil compared to control soil samples (P < 0.05). Sphingomonas, Nitrospira, and Reyranella were significantly enriched in soil samples near the lightning rod compared to soil samples far from the lightning rod. Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that adenosine/AMP kinase, chitodextrinase, flavorubredoxin, nucleotide metabolism, and carbohydrate digestion and absorption were significantly enriched in the rhizosphere soil samples near the lightning rod compared to the control samples (P < 0.05). β diversity analysis indicated the grounding of the lightning rod contributed to the community differentiation of rhizosphere bacteria. Amino acids, polyphenols, and soluble sugar increased in Pu-erh tea near the lightning rod, while the contents of catechin and anthocyanin decreased in Pu-erh tea near the lightning rod compared with the control sample (P < 0.05). Significant correlations were found among microbial indicators, soil properties, and Pu 'er tea components. This study serves as the first report on the effects of lightning rods on soil properties, microecology, and plant metabolism, which promotes the understanding of the biological effects of lightning, and provides a reference for the rational use of lightning resources.

Lightning rods have been developed to prevent damage caused by lightning to organisms. However, the biological effect of the current transmitted into the soil through lightning rods is unknown. In this study, we analyzed the effects of lightning on soil properties, the microbial community, and the active components of Pu-erh tea (

For the urgent need for fermentation control and product quality improvement of Pu-erh tea, gas chromatography-mass spectrometry and odor activity value (OAV) were used to comprehensively investigate the flavor-active compounds during artificial fermentation of Pu-erh tea. A flavor wheel was constructed to expound the sensory attributes evolution during fermentation. With an increased total volatiles content, 43 were significantly up-regulated and 30 were down-regulated among 131 detected volatiles. Key active compounds of three aroma types, namely fresh fragrance, fruit-fungus fragrance and stale-Qu fragrance, were analyzed based on OAV. β-damascenone was firstly found contributing most to the aroma of Pu-erh tea, followed by 1,2,3-methoxybenzene and (E,E)-2,4-nonadienal. γ-terpinene, linalool, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, and 4-ethylveratrol were identified as the potential markers responsible for aroma differences among three fermentation stages. Finally the metabolic evolution of key flavor-active compounds were systematically summarized. This study provides significant guidance in fermentation control and new product development of Pu-erh tea.

The preparation of titanium silicalite-1 (TS-1) containing Al (Al-TS-1) and its catalytic oxidation properties were investigated systematically. The features of Al-TS-1 were characterized using X-ray diffraction, ultraviolet-visible spectroscopy, inductively coupled plasma atomic emission spectroscopy, 27Al magic-angle spinning and 29Si magic-angle spinning nuclear magnetic resonance spectroscopies, and scanning electron microscopy. The results showed that incorporation of Al into the TS-1 framework influences the amount of framework Ti in Al-TS-1. However, when the Al/Si ratio is lower than 0.005, the amount of framework Ti in Al-TS-1 is hardly affected. Neither the Al centers nor the Ti centers in the Al-TS-1 framework influence the acidic catalytic and catalytic oxidation performance. Al in the Al-TS-1 framework suppressed desilication of silica species adjacent to framework Ti species in Al–TS-1 in a basic catalytic system, so Ti active sites in the Al–TS-1 framework could be protected.

Titanium silicalite-1 (TS-1) has been successfully synthesized in ultralow molar ratio of TPAOH/SiO2 by two-step and multistep hydrolysis process, where the molar ratio of tetrapropylammonium hydroxide/silica (TPAOH/SiO2) could be reduced to 0.08 and 0.065, respectively. Combined characterization of X-ray diffraction (XRD), N2 adsorption–desorption, scanning electron microcopy (SEM), Fourier transform infrared spectroscopy (FT-IR), UV–vis spectroscopy, and thermal gravimetric (TG) analysis shows that currently synthesized TS-1 samples have the typical “blackberry” morphology, and the particle size is around 300–400 nm, similar to that of the conventional TS-1 synthesized at a high molar ratio of TPAOH/SiO2 (>0.18). Additionally, currently synthesized TS-1 exhibits excellent catalytic oxidation performance in epoxidation of alkene and ammoximation of ketone, even better than that of conventional TS-1. Obviously, fast hydrolysis of a small part of TEOS at a high concentration of TPA+ in the first step induc...

A facile strategy is proposed to construct a highly active oxidation catalyst with optimally distributed titanium coordination states containing "TiO4" and "TiO6" species. The "TiO6" species in TS-1(+) shows a superior catalytic oxidation activity, which is 2-3 times that of "TiO4" species in TS-1.

A typical volcano-shaped curve has been found in heterogeneous catalytic systems containing titanosilicates for the first time. A new reactive intermediate with double H-bonds is proposed. Systematic results clearly evidence another H-bond formed between the high-electronegativity atom of the H-bond acceptor and the H(end) atom of Ti-Oα-Oβ-H(end).

Fluorine species were successfully implanted into a MWW-type titanosilicate via post-treatment, which generates the SiO3/2F units in the zeolite framework. The incorporated fluorine species significantly improved the catalytic performance in the epoxidation of alkenes as a result of enhancing the Lewis acid strength and the hydrophobicity of the zeolite.