[Effects of paramagnetic material on the characteristics of low field nuclear magnetic resonance signals and water measurement in different textured soils.] / é¡ºç£ç‰©è´¨å¯¹åœŸå£¤ä½Žåœºæ ¸ç£å ±æŒ¯ä¿¡å·ç‰¹å¾åŠå«æ°´é‡æµ‹å®šçš„å½±å“.

Nuclear magnetic resonance (NMR) technology has been applied in soil science due to the characte-ristics of high efficiency, rapidity, no damage to soil structure, and harmlessness to the human body. However, the effect of the presence of paramagnetic materials in soils on the characteristics of NMR signals was still unclear. In this study, we investigated the effects of paramagnetic material on the low field nuclear magnetic (LF-NMR) signals and soil water content measurement in soils with different texture. The results showed that the LF-NMR signal of soil water could reach about 150, while that of all the solid materials including soil minerals, organic matter and microbes was less than 0.3, which was relatively negligible. Compared with the NMR signals produced by solid materials in soils, soil texture and paramagnetic material had stronger impact on the measured LF-NMR signals of soil water. LF-NMR equipment had a relaxation time monitoring blind area, and the loss of NMR signal was mainly due to the acceleration of the relaxation process of hydrogen protons in water by magnetic materials, resulting in extremely fast LF-NMR signals feed back by water in small pores that could not be captured by monitoring equipment. For loamy fluvo-aquic soil (1.2%) and clay loamy black soil (1.3%) with low paramagnetic material contents, the loss of LF-NMR signals was not large, which was linearly related to soil water content. For clayey red soil with high content of clay (45.3%) and paramagnetic materials (4.0%), a part of the LF-NMR signals would be lost in the measurement, and the monitored LF-NMR signal was not linearly related to the soil water content. In addition, external addition of paramagnetic materials (3.0 g·L-1 MnCl2 solution) would further reduce the LF-NMR signals that could be monitored in black and red soils. The maximum signal loss rates of black soil and red soil were 41.0% and 46.7%, respectively, which greatly changed the quantitative relationship between it and soil water content. Therefore, the influence of paramagnetic materials on the LF-NMR signals should be reduced first through correction when using LF-NMR to measure the water content of clay soil with rich internal paramagnetic materials (>1.3%) or external addition of paramagnetic materials. Our results would provide valuable insights into the study of soil water content measurement and soil pore structure analysis using low field nuclear magnetic resonance technology.

[Effects of exogenous attapulgite addition on water conservation function of reclaimed soils in a semi-arid mining area]. / å¤–æºå‡¹å‡¸æ£’åœŸæ·»åŠ å¯¹åŠå¹²æ—±çŸ¿åŒºå¤åž¦åœŸå£¤æ°´åˆ†æ¶µå »åŠŸèƒ½çš„å½±å“.

Large-scale mining has greatly damaged vegetation and caused ecological degradation in the semi-arid area in China. It is urgent to restore the vegetation to solve the deteriorating ecological and environmental problems in mining area. How to reclaim soils for effectively storing and utilizing precipitation is the primary issue for vegetation restoration in the area. In this study, we proposed to take the mixture of attapulgite clay and local sandy soils as covering materials to improve the weak water conservation function of soils in mining areas, and studied the effects of the addition of attapulgite clay on soil infiltration, drainage and water storage sampled from the Shenmu mining area. The results showed that, with increasing application rates of attapulgite clay, the cumulated infiltration volumes decreased by 4.8%-37.4%, the infiltration rates dropped by 6.4%-46.3%, the wetting front advance rates decreased by 9.8%-116.9%, the saturated hydraulic conductivities decreased by 14.3%-59.5%, the drained water volumes reduced by 0.3%-4.3% for 24 hours and by 0.3%-2.5% for 72 hours, and the maximum soil water storages increased by 1.6%-22.4%. The maximum effect of attapulgite clay peaked at the application rate of 150 t·hm-2. Considering the economic cost, the optimum application rate should be 30-150 t·hm-2. The results syste-matically revealed the mechanism of reclaiming mining soils with attapulgite clay to restore the function of water conservation, and demonstrated that attapulgite clay is an effective material for soil reclamation in the semi-arid mining area, which can provide references for soil reclamation and ecological restoration in the semi-arid mining area.

Fragile X-Related Protein 1 (FXR1) Promotes Trophoblast Migration at Early Pregnancy via Downregulation of GDF-15 Expression.

Fragile X-related protein 1 (FXR1) is an RNA-binding protein that can regulate specific mRNA decay in cells. Our previous study showed that FXR1 expression was significantly decreased in trophoblasts from patients with unexplained recurrent spontaneous abortion (RSA); however, the role of FXR1 in trophoblast function during early placenta development has not been fully elucidated. In this study, we found that knockdown of FXR1 using siRNA effectively inhibited the migration of HTR-8 cells and extravillous trophoblast (EVT) outgrowth in an ex vivo extravillous explant culture model. Furthermore, through analysis of a panel of cytokines, we found that the GDF-15 protein was upregulated after knockdown of FXR1 in HTR-8/SVneo cells. This was further confirmed by western blotting and immunofluorescence in HTR-8/SVneo cells and an extravillous explant. Our data also showed that FXR1 expression was downregulated and GDF-15 was upregulated in chorionic villous tissues from RSA patients compared with those from healthy controls (HCs). Further, immunohistochemistry showed a strong expression of GDF-15 in chorionic villous tissue in the RSA group, which was mainly distributed in villous trophoblasts (CTBs) and syncytiotrophoblasts (STBs). Moreover, knockdown of GDF-15 enhanced the migration of HTR-8 cells, while overexpression of GDF-15 using plasmid or treatment with recombinant human GDF-15 protein inhibited trophoblast migration. Importantly, RNA-binding protein immunoprecipitation showed that FXR1 directly bound to the 3'-UTR of GDF-15 mRNA to promote GDF-15 mRNA decay. Together, our data provide new insight into the function of FXR1 in human placenta via regulation of GDF-15 expression in trophoblasts and suggest a possible pathological process involved in RSA.

[Technology and provenance of proto-porcelain of Yingguo graveyard in Henna province].

Protoporcelain is a kind of multi-epoch and multi-culture-area ceramic hangover with iterative appearance, and it is the important interim of the development from pottery to porcelain. Therefore, its origin, development and prevalence problems, which relate directly to China development mode and Shang Zhou culture visage, are the important discussion of archaeology, ceramic technic history and chemistry history, and have important learning value. XRF and XRD technique were used to determine several shreds excavated from Yingguo graveyard site in Henan province. The result shows that some samples have abnormity phosphor, hinting that some plant or wood ash was ever used as raw material. From the rate of Ca/Al and P/Al and comparative analysis, we discovered that proto-porcelain of Yingguo site has different chemical character compared to south production.