The iron stable isotope compositions (δ56Fe) and iron valence states of ultrahigh‐pressure eclogites from Bixiling in the Dabie orogen belt, China, were measured to trace the changes of geochemical ...conditions during vertical transportation of earth materials, for example, oxygen fugacity. The bulk Fe3+/ΣFe ratios of retrograde eclogites, determined by Mössbauer spectroscopy, are consistently higher than those of fresh eclogites, suggesting oxidation during retrograde metamorphism and fluid infiltration. The studied eclogites (five samples) display limited mid‐ocean ridge basalts (MORB)‐like (~0.10‰) δ56Fe values, which are indistinguishable from their protoliths, that is, gabbro cumulates formed through differentiation of mantle‐derived basaltic magma. This suggests that Fe isotope fractionation during continental subduction is limited. Garnet separates display limited δ56Fe variation ranging from −0.08 ± 0.07 ‰ to 0.02 ± 0.07‰, whereas coexisting omphacite displays a large variation of δ56Fe values from 0.15 ± 0.07‰ to 0.47 ± 0.07‰. Omphacite also has highly variable Fe3+/ΣFe ratios from 0.367 ± 0.025 to 0.598 ± 0.024, indicating modification after peak metamorphism. Omphacite from retrograde eclogites has elevated Fe3+/ΣFe ratios (0.54–0.60) compared to that from fresh eclogites (~0.37), whereas garnet displays a narrow range of ferric iron content with Fe3+/ΣFe ratios from 0.039 ± 0.013 to 0.065 ± 0.022. The homogenous δ56Fe values and Fe3+/ΣFe ratios of garnet suggest that it survived the retrograde metamorphism and preserved its Fe‐isotopic features and ferric contents of peak metamorphism. Because of similar diffusion rates of Fe and Mg in garnet and omphacite, and constant Δ26Mgomphacite‐garnet values (1.14 ± 0.04‰), equilibrium iron isotope fractionation between garnet and omphacite was probably achieved during peak metamorphism. Elevated Fe3+/ΣFe ratios of omphacite from retrograde eclogites and variant Δ56Feomphacite‐garnet values of the studied eclogites (0.13 ± 0.10‰ to 0.48 ± 0.10‰) indicate that oxidized geofluid infiltration resulted in the elevation of δ56Fe values of omphacite during retrograde metamorphism.
This study evaluated the effects of Bacillus fermentation on soybean meal protein (SBMP) microstructure and major anti‐nutritional factors (ANFs) in soybean meal (SBM). The Bacillus siamensis isolate ...JL8 producing high yield of protease at 519·1 U g−1 was selected for the laboratory production of fermented soybean meal (FSBM). After 24 h fermentation, the FSBM showed better properties compared with those of SBM, the ANFs such as glycinin, β‐conglycinin and trypsin inhibitor significantly decreased by 86·0, 70·3 and 95·01%, while in vitro digestibility and absorbability increased by 8·7 and 18·9% respectively. Scanning electron microscopy (SEM) image of fermented soybean meal protein showed smaller aggregates and looser network than that of SBMP. Secondary structure examination of proteins revealed fermentation significantly decreased the content of β‐sheet structure by 43·2% and increased the random coil structure by 59·9%. It is demonstrated that Bacillus fermentation improved the nutritional quality of SBM through degrading ANFs and changing the microstructure of SBMP.
Significance and Impact of the Study
There is limited information about the structural property changes of soybean protein during fermentation. In this study, physicochemical analysis of soybean meal protein showed evidence that the increase in in vitro digestibility and absorbability of fermented soybean meal reflected the decrease in β‐conformation and destruction of original structure in soybean meal protein. The results directly gained the understanding of nutritional quality improvement of soybean meal by Bacillus fermentation, and supply the potential use of Bacillus siamensis for fermented soybean meal production.
Significance and Impact of the Study: There is limited information about the structural property changes of soybean protein during fermentation. In this study, physicochemical analysis of soybean meal protein showed evidence that the increase in in vitro digestibility and absorbability of fermented soybean meal reflected the decrease in β‐conformation and destruction of original structure in soybean meal protein. The results directly gained the understanding of nutritional quality improvement of soybean meal by Bacillus fermentation, and supply the potential use of Bacillus siamensis for fermented soybean meal production.
Aim To investigate the potential of iodine concentration (IC) determined using virtual monochromatic spectral computed tomography (CT) to predict the response of gastric carcinomas to preoperative ...neoadjuvant chemotherapy (NC). Materials and methods A total of 20 patients were enrolled who underwent two spectral CT examinations (1 week before and two cycles after NC). The percentage change in tumour thickness (%ΔCWT) and in IC on the arterial phase (%ΔIC-a) and venous phase (%ΔIC-v) after NC were calculated and compared for different histopathological regression grades and response groups. The diagnostic efficacies to discriminate good response (GR) and poor response (PR) of the above three parameters were evaluated using receiver operating characteristic (ROC) curves. Results The decrease rate of %ΔIC-a for the GR group was higher than that for the PR group (−0.59 −0.76, −0.20 versus −0.11 −0.75, 0.92, p =0.012). There was no significant difference in the %ΔIC-v and %ΔCWT values between the GR and PR groups ( p =0.076 and p =0.779, respectively). The areas under the ROC curve (AUC) values were 0.857, 0.762, and 0.542 for %ΔIC-a, %ΔIC-v, and %ΔCWT, respectively, in the response prediction. The cut-off value for identifying PR was a decrease rate of <52.9% for %ΔIC-a, and the sensitivity and specificity values were 0.857 and 0.833. Conclusion Changes in the IC for gastric carcinomas following NC were detected using spectral CT and correlated with histopathological regression. The prediction efficacy for IC was better than that for tumour thickness, with IC on the arterial phase being a better predictor than IC on the venous phase.
Background
Altered visceral sensation is common in irritable bowel syndrome (IBS) and nerve growth factor (NGF) participates in visceral pain development. Sodium butyrate (NaB) could induce colonic ...hypersensitivity via peripheral up‐regulation of NGF in animals. Enteric glial cells (EGCs) appear to be an important source of NGF. Whether butyrate could induce visceral hypersensitivity via increased EGC‐derived NGF is still unknown.
Methods
CRL‐2690 cells were used for transcriptome analyses after butyrate treatment. Rats received butyrate enemas to induce colonic hypersensitivity. Colorectal distention test was performed to assess visceral sensitivity. Immunofluorescence studies were used to evaluate the co‐expression of glial fibrillary acidic protein (GFAP) and NGF or growth associated protein 43 in animal model. NGF expression in rat colon was also investigated. In vitro, CRL‐2690 cells were stimulated with NaB or trichostatin A (TSA). NGF or GFAP expression was also examined.
Key Results
Transcriptome analyses showed that butyrate induced marked changes of genes expression related to neurotrophic signaling pathways. NaB‐treated rats showed increased visceral sensitivity. An improved NGF expression level was observed in NaB‐treated rats. Meanwhile, a 2.1‐fold increase in co‐expression of GFAP and NGF was also determined in rats received NaB enemas. In cultured cells, both NaB and TSA treatment could cause obvious NGF expression. Thus, butyrate might regulate EGC function via histone deacetylase inhibition.
Conclusions & Inferences
Butyrate‐EGC interplay may play a pivotal role in regulation of NGF expression and the development of colonic hypersensitivity in IBS‐like animal model.
Our study illustrated that butyrate promoted the secretion of NGF from enteric glial cells (EGCs) and contributed to visceral hypersensitivity in rats. The results clarified the potential unignorable source of NGF from EGC and highlighted the important role of EGC in pathogenesis of irritable bowel syndrome (IBS).
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