4 research outputs found

    An RNA-Sequencing Study of the Genes and Metabolic Pathways Involved in <i>Aspergillus niger</i> Weathering of Potassium Feldspar

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    <div><p>Microbial transformation of potassium feldspar to produce organic composite potassium fertilizer is recognized to be an important method of effective use of the huge reserves of low grade K<sup>+</sup>-bearing rock in China. The mechanism underlying microbial weathering of silicate minerals is still unclear, and this is an obstacle to practical methods of application. To thoroughly understand the molecular mechanism responsible for the weathering of potassium feldspar by <i>Aspergillus niger</i> at a molecular level, high-throughput RNA-sequencing (RNA-seq) and treatment with different potassium sources (cultured in Czapek medium with soluble K<sup>+</sup> or potassium feldspar) were used to investigate the differentially expressed genes of <i>A</i>. <i>niger</i> associated with potassium feldspar weathering and the related metabolic pathways. A series of differentially expressed genes related to the synthesis and transportation of organic acids, polysaccharides, and proteins (enzymes) were found to be closely associated with the K<sup>+</sup> released from minerals through bioinformatic analysis. In addition, 12 genes that showed apparent expression differences by RNA-seq analysis and are relevant to organic acid synthesis, protein modification, maintenance of cellular homeostasis, and material transportation, were selected to be further verified using RT-qPCR. Compared to the fungal samples cultured with soluble K<sup>+</sup>, those with potassium feldspar have certain genes that are more up-regulated, such as the genes for Na<sup>+</sup>,K<sup>+</sup>-ATPase (447.6 multiples), cystathionine beta-synthase (5.6 multiples), cysteine synthase (9 multiples), and glutathione synthase (3.5 multiples). The analysis indicates that <i>A. niger</i> weathering of potassium feldspar is due to the synergistic effect of many factors including the up-regulation of certain genes and activation of related metabolite pathways. The research improves our understanding of the mechanisms of microbial weathering of silicate minerals.</p></div

    Parameter study on characteristic pulse diagram of polycystic ovary syndrome based on logistic regression analysis

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    This study aimed to explore the parameters of the independent predictive characteristic pulse diagram of polycystic ovary syndrome (PCOS) by analysing the pulse characteristics between healthy women and the PCOS group. A total of 278 women were recruited for this study. Pulse wave parameters were collected by the pulse spectrum analyser. The single-factor analysis of the pulse diagram parameters was used to identify significant indicators, and the logistic regression analysis was carried out on the above indicators with statistical differences to obtain independent predictors. According to the single-factor and multi-factor analyses, h1, h5, h3/h1, t, t1 and t5 were independent predictors of PCOS diagnosis. The results showed that PCOS patients had a faster heart rate, decreased left ventricular systolic function and decreased aortic compliance compared to healthy individuals. These findings suggested that the characteristic pulse parameters screened out are valuable for the diagnosis of PCOS.IMPACT STATEMENTWhat is already known on this subject? Polycystic ovary syndrome (PCOS) is a common gynecological reproductive endocrine and metabolic disease, which is significant for screening and early intervention in the disease. However, due to the lack of pulse’s diagnostic evidence of PCOS, there is still an unknown area in the research on the correlation between PCOS and pulse diagram parameters.What do the results of this study add? This study fills the gap between the research on PCOS and pulse wave. The study also shows that the pulse characteristic parameters h1, h5, h3/h1, t, t1, and t5 are independent predictors of PCOS, suggesting that the patients have a higher heart rate, lower ventricular systolic function, and aortic compliance than healthy individuals.What are the implications of these findings for clinical practice and/or further research? Prominent risk factors for pulse parameters associated with the occurrence of PCOS facilitate early screening and diagnosis of the disease. The objectification of pulse diagnosis helps to establish a health management model, which can be used for the accurate assessment and treatment of PCOS by traditional Chinese medicine (TCM). It provides a clinical reference for the study of pulse diagnosis objectification. What is already known on this subject? Polycystic ovary syndrome (PCOS) is a common gynecological reproductive endocrine and metabolic disease, which is significant for screening and early intervention in the disease. However, due to the lack of pulse’s diagnostic evidence of PCOS, there is still an unknown area in the research on the correlation between PCOS and pulse diagram parameters. What do the results of this study add? This study fills the gap between the research on PCOS and pulse wave. The study also shows that the pulse characteristic parameters h1, h5, h3/h1, t, t1, and t5 are independent predictors of PCOS, suggesting that the patients have a higher heart rate, lower ventricular systolic function, and aortic compliance than healthy individuals. What are the implications of these findings for clinical practice and/or further research? Prominent risk factors for pulse parameters associated with the occurrence of PCOS facilitate early screening and diagnosis of the disease. The objectification of pulse diagnosis helps to establish a health management model, which can be used for the accurate assessment and treatment of PCOS by traditional Chinese medicine (TCM). It provides a clinical reference for the study of pulse diagnosis objectification.</p

    The Up-regulation of Carbonic Anhydrase Genes of <i>Bacillus mucilaginosus</i> under Soluble Ca<sup>2+</sup> Deficiency and the Heterologously Expressed Enzyme Promotes Calcite Dissolution

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    <div><p>Molecular mechanisms and gene regulation are of interest in the area of geomicrobiology in which the interaction between microbes and minerals is studied. This paper focuses on the regulation of the expression of carbonic anhydrase (CA) genes in <i>Bacillus mucilaginosus</i> and the effects of the expression product of the <i>B. mucilaginosus</i> CA gene in <i>Escherichia coli</i> on calcite weathering. Real-time fluorescent quantitative PCR (RT-qPCR) was used to explore the relationship between CA gene expression in <i>B. mucilaginosus</i> and promotion of calcite dissolution under condition of Ca<sup>2+</sup> deficiency. The results showed that adding calcite to the medium, which lacks Ca<sup>2+</sup>, can up-regulate the expression of the bacterial CA genes to accelerate calcite dissolution for bacterial growth. CA genes from <i>B. mucilaginosus</i> were transferred into <i>E. coli</i> by cloning. We then employed crude enzyme extract from the resultant <i>E. coli</i> strain in calcite dissolution experiments. The enzyme extract promoted calcite dissolution. These findings provide direct evidence for the role of microbial CA on mineral weathering and mineral nutrition release.</p></div

    Responses of Organic Phosphorus Fractionation to Environmental Conditions and Lake Evolution

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    Geochemical fractionation is used to assess the significance of environmental factors on organic phosphorus (OP) pools in sediments. Labile, moderately labile, and nonlabile OP pools in the sediments from Lake Hulun, Inner Mongolia, were fractionated, and their responses to environmental conditions and lake evolution were investigated based on the spatial and vertical distribution of OP fractionations. In light of the recalcitrant characteristics of organic matter (OM) in different environmental conditions, the pH presents significant negative effects on the amount of labile OP, while water depth shows an important role in regulating the distribution between the moderately labile and nonlabile OP pools. A latitudinal zonation in the distribution of OP pools in surface sediments from different lakes was apparent with this zonation likely linked to the gradient effects of climate and anthropogenic activities on OM decomposition and thereby on the sediments capacity to hold phosphorus. These results show that OM plays a role in governing the impacts of weather and environmental factors on OP fractionation in aquatic environments. This work suggests that OP pools in the sediment core could be used as an archive for environmental conditions and lake evolution
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