The China–Russia Crude Oil Pipeline (CRCOP) was built to transport Siberian crude oil across 1030km of frozen ground. The Chinese portion of the CRCOP crosses 441km of discontinuous permafrost zones ...along the eastern flanks of the Da Xing'anling (Hinggan) Mountains. Significant thaw settlement of some of the pipeline foundation soils has occurred since the pipeline began operating in January 2011. The differential thaw settlement around the pipeline at the transitions between the thaw-settling and thaw-stable zones may lead to displacement or even buckling of the pipeline. To evaluate the engineering safety and long-term stability of pipeline foundations, ground-penetrating radar (GPR) was used to detect the freeze–thaw states of pipeline foundation soils in the permafrost zones. From April 2012 to November 2013, a total of 2780m of GPR profiles and 62 cross-sections (perpendicular to the CRCOP route) were obtained at eight GPR study sites on various terrains and vegetative coverage, with different thermal insulation configurations around the pipe, and with and without thermosyphons installed. The GPR profiles were interpreted and cross-checked with data from drilling, hand-dug pit or trench excavations, and ground temperature measurements. The results showed that the foundation soils around the pipeline were thawing, with maximum thaw depths under the pipeline of about 1.1m to 4.5m from the pipe bottom and increased maximum thaw depths of 0.5m to 3.7m during the period of this study. However, GPR profiles from the areas with dense vegetative coverage, and with pipe insulation of 80-mm-thick extruded polystyrene (XPS), and also with vertical thermosyphons installed, showed that permafrost foundation soils were thermally better protected, with only minor thaw settlement. The thermal states of pipeline foundation soils and the underlying permafrost varied markedly with different terrains. The drainage patterns and engineering activities, especially the heating from operating oil flows at an average annual oil temperature of 7.7°C (with a range of 0.7°C to 20.4°C) along the pipeline route may have been responsible for the extensive and substantial thaw subsidence in the ice-rich permafrost zones. Additionally, there was positive feedback between the thaw subsidence of ground surface in the vicinity of the pipeline route and the thaw settlement of the pipeline foundation soils. The greater the earth surface subsidence, the more surface water ponding and soil disturbances, and even more progressive thawing. Therefore, some measures are recommended for stabilizing the pipeline foundation soils. The research results also indicate that the GPR method is effective, nondestructive, and convenient for evaluating the spatiotemporal extent and development processes of the freeze–thaw states of pipeline foundation soils and the underlying permafrost.
•Evaluation of thermal states of pipeline foundation soils at 8 sites along the CRCOP using GPR.•GPR records interpreted with the help of stratigraphic and freeze–thaw information from boreholes and hand-dug trenches.•GPR results compared with monitored results, model predictions, and centrifuge model test results.•Insulation and thermosyphon effects of foundation soils did not achieve original expectations, better design, or retrofits recommended.•Causal analysis for larger than anticipated, proactive measures, advantages, and limitations of using GPR for measuring thaw depths of pipeline foundation soils were provided and advised.
The effect of air pollution on the changing pattern of glomerulopathy has not been studied. We estimated the profile of and temporal change in glomerular diseases in an 11-year renal biopsy series ...including 71,151 native biopsies at 938 hospitals spanning 282 cities in China from 2004 to 2014, and examined the association of long-term exposure to fine particulate matter of <2.5 μm (PM
) with glomerulopathy. After age and region standardization, we identified IgA nephropathy as the leading type of glomerulopathy, with a frequency of 28.1%, followed by membranous nephropathy (MN), with a frequency of 23.4%. Notably, the adjusted odds for MN increased 13% annually over the 11-year study period, whereas the proportions of other major glomerulopathies remained stable. During the study period, 3-year average PM
exposure varied among the 282 cities, ranging from 6 to 114 μg/m
(mean, 52.6 μg/m
). Each 10 μg/m
increase in PM
concentration associated with 14% higher odds for MN (odds ratio, 1.14; 95% confidence interval, 1.10 to 1.18) in regions with PM
concentration >70 μg/m
We also found that higher 3-year average air quality index was associated with increased risk of MN. In conclusion, in this large renal biopsy series, the frequency of MN increased over the study period, and long-term exposure to high levels of PM
was associated with an increased risk of MN.
In eutrophic lakes, heterotrophic bacteria are closely associated with algal detritus and play a crucial role in nutrient cycling. However, the seasonal and spatial dynamics of free-living (FL) and ...particle-attached (PA) bacteria and the environmental factors shaping this relationship remain poorly understood. To address this issue, we explored the spatiotemporal patterns of bacterial community composition (BCC) in Lake Taihu, China, using terminal restriction fragment length polymorphism (T-RFLP) and 454-tag pyrosequencing of 16S rRNA gene. We generated a total of 218,027 high quality non-cyanobacterial sequence reads that resulted in 4940 OTUs (97% cutoff), with Actinobacteria, β- and α-proteobacteria being the predominant taxa. Although PA communities contained significantly higher alpha-diversity than FL ones, we found that 59% of OTUs, that accounted for 96% of the total reads, were shared by both communities. The high degree of overlap between FL and PA communities indicates a high rate of dispersal potential, highlighting an underestimated connectivity and potentially similar ecological role for these two components. Distinct seasonal trends were recorded in both FL and PA communities, while spatial differences in BCC were small. In addition, both FL and PA bacterial communities exhibited similar patterns and synchrony, correlated to water temperature, nitrate and total suspended solids (TSS). Accordingly, the effects of eutrophication and hydrodynamics on the phylogenetic overlap and diversity between FL and PA communities were discussed.
Sports is promoted in China through e-commerce applications in all age groups, particularly among the retied and people with disability. E-commerce thus plays the educational role in developing ...awareness about sports. Physical fitness is also promoted through such e-commerce activities and makes a significant educational effect on the whole society. Physical health programs have become an integral part of public awareness education making them a common habit. However, China still lacks relevant theoretical research, especially in e-commerce systems based on complex networks. This paper analyzed e-commerce network settings and complex system frameworks based on the complexity networks. In the light of these analyses, national sports' status quo was summarized, and the significance of developing national sports was emphasized. The study used literature survey, comparative research, questionnaire survey, mathematical statistics, and logic analysis methods, and used several types of classifications of the sample of the study, namely the retired workers, the disabled, and the underdeveloped regions in Northwest China. According to statistics, the results show that the establishment of e-commerce outlets based on complex networks had a positive effect on retired employees as it increased their awareness and participation in sports. E-commerce, in spite of all its complexities, has thus provided a convenient online fitness platform for retired employees, disabled people, and people in the backward regions. Simultaneously, various e-commerce websites and mobile Apps have has also played an active role to promote sports activities among these sections of society. The study concluded that an e-commerce network setting based on complex networks could promote sports in China and ultimately affect people's health and fitness.
Surfactin is a cyclic lipopeptide that is of great industrial use owing to its extraordinary surfactant power and antimicrobial, antiviral, and antitumor activities. Surfactin is synthesized by a ...condensation reaction in microbes, which uses fatty acids and four kinds of amino acids (L-glutamate, L-aspartate, L-leucine and L-valine) as precursors. Surfactin biosynthesis could be improved by increasing the supply of fatty acids; however, the effect of the regulation of amino acid metabolism on surfactin production was not yet clear.
In this study, we aimed to improve surfactin production in B. subtilis by repressing the genes on the branch metabolic pathways of amino acid biosynthesis using CRISPRi technology. First, 20 genes were inhibited individually, resulting in 2.5- to 627-fold decreases in transcriptional level as determined by RT-qPCR. Among the 20 recombinant strains, 16 strains obtained higher surfactin titres than that produced by the parent BS168NU-Sd strain (the surfactin production of BS168NU-Sd with only dCas9 but no sgRNA expression was 0.17 g/L). In particular, the strains in which the yrpC, racE or murC genes were inhibited individually produced 0.54, 0.41, or 0.42 g/L surfactin, respectively. All three genes are related to the metabolism of L-glutamate, whose acylation is the first step in the surfactin condensation reaction. Furthermore, these three genes were repressed in combination, and the strain with co-inhibition of yrpC and racE produced 0.75 g/L surfactin, which was 4.69-fold higher than that of the parent strain. In addition, the inhibition of bkdAA and bkdAB, which are related to the metabolism of L-leucine and L-valine, not only improved surfactin production but also increased the proportion of the C
isoform.
This study, to the best of our knowledge for the first time, systematically probed the regulatory effect of increasing the supply of amino acids on surfactin production. It provided an effective strategy and a new perspective for systematic studies on surfactin and other amino acid-derived chemicals.
Bone marrow mesenchymal stem cells (BMSCs) exhibit the capacity to self-renew and differentiate into multi-lineage cell types, including osteoblasts, which are crucial regulators of fracture healing. ...Thus, this study aims to investigate the effect of microRNA (miR)-22-3p from BMSC-derived EVs on osteogenic differentiation and its underlying mechanism.
Extracellular vesicles (EVs) were isolated from BMSCs and taken up with BMSCs. Dual-luciferase reporter gene assay was used to verify the binding relationship between miR-22-3p and FTO. Loss- and gain-of-function experiments were performed to determine the roles of EV-delivered miR-22-3p and FTO in osteogenic differentiation as well as their regulatory role in the MYC/PI3K/AKT axis. To determine the osteogenic differentiation, ALP and ARS stainings were conducted, and the levels of RUNX2, OCN, and OPN level were determined. In vivo experiment was conducted to determine the function of EV-delivered miR-22-3p and FTO in osteogenic differentiation, followed by ALP and ARS staining.
miR-22-3p expression was repressed, while FTO expression was elevated in the ovariectomized mouse model. Overexpression of miR-22-3p, EV-delivered miR-22-3p, increased ALP activity and matrix mineralization of BMSCs and promoted RUNX2, OCN, and OPN expressions in BMSCs. miR-22-3p negatively targeted FTO expression. FTO silencing rescued the suppressed osteogenic differentiation by EV-delivered miR-22-3p inhibitor. FTO repression inactivated the MYC/PI3K/AKT pathway, thereby enhancing osteogenic differentiation both in vivo and in vitro.
In summary, miR-22-3p delivered by BMSC-derived EVs could result in the inhibition of the MYC/PI3K/AKT pathway, thereby promoting osteogenic differentiation via FTO repression.
This study is aimed to elucidate the molecular mechanism of lncRNA SNHG7 on pre-eclampsia (PE).
The expression of SNHG7, miR-214-5p and TWIST1 in PE placental tissues was detected by qRT-PCR. The ...regulatory mechanism of SNHG7/miR-214-5p/TWIST1 axis on PE was determined using MTT, wound healing, transwell invasion, and western blot assays.
In PE pregnancies, SNHG7 and TWIST1 were decreased, while miR-214-5p was increased.The elevated miR-214-5p and decreased TWIST1 partly eliminated the promoting effects of SNHG7 up-regulation on the viability and metastasis of JEG-3 cells.
Up-regulated SNHG7 protects against PE through modulating the miR-214-5p/TWIST1 axi.
Disturbances in protein folding and membrane compositions in the endoplasmic reticulum (ER) elicit the unfolded protein response (UPR). Each of three UPR sensory proteins-PERK (PEK/EIF2AK3), IRE1, ...and ATF6-is activated by ER stress. PERK phosphorylation of eIF2 represses global protein synthesis, lowering influx of nascent polypeptides into the stressed ER, coincident with preferential translation of ATF4 (CREB2). In cultured cells, ATF4 induces transcriptional expression of genes directed by the PERK arm of the UPR, including genes involved in amino acid metabolism, resistance to oxidative stress, and the proapoptotic transcription factor CHOP (GADD153/DDIT3). In this study, we characterize whole-body and tissue-specific ATF4-knockout mice and show in liver exposed to ER stress that ATF4 is not required for CHOP expression, but instead ATF6 is a primary inducer. RNA-Seq analysis indicates that ATF4 is responsible for a small portion of the PERK-dependent UPR genes and reveals a requirement for expression of ATF4 for expression of genes involved in oxidative stress response basally and cholesterol metabolism both basally and under stress. Consistent with this pattern of gene expression, loss of ATF4 resulted in enhanced oxidative damage, and increased free cholesterol in liver under stress accompanied by lowered cholesterol in sera.
Gearbox bearings play an important role in wind power generation system. Their regular and stable operation will increase wind turbine power generation and improve the economic efficiency of wind ...farms. They often fail because they work under complex wind conditions. Therefore, it is necessary to find the fault early. The vibration signal of the gearbox bearing has the characteristics of volatility and continuity. Traditional bearing fault diagnosis methods are often based on signal analysis and feature selection, and the process is relatively complex. Deep learning methods can extract and select features automatically, thereby reducing the workload. A fault diagnosis method based on deep learning is proposed in this study. This method combines a one-dimensional convolutional neural network (1DCNN), support vector machine (SVM) classifier, and 1DCNN adaptively extracts features. The extracted features are input into the SVM classifier, and particle swarm optimization (PSO) is used to optimize the SVM classifier. The results show that the proposed fault diagnosis method is effective for fault diagnosis of wind turbine gearbox bearings. This method improves the precision and accuracy of diagnosis when compared to other methods.
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