[Temporal and Spatial Distribution Characteristics and Source Analysis of Nitrate in Surface Water of Wuding River Basin].

The Wuding River Basin is a first-class tributary of the Yellow River, and the quality of its water ecological environment has a profound impact on the ecological protection and high-quality development of the Yellow River Basin. In order to identify the source of nitrate pollution in the Wuding River Basin, surface water samples of the Wuding River were collected from 2019 to 2021, and the temporal and spatial distribution characteristics and influencing factors of nitrate concentration in surface water in the basin were explored. Nitrogen and oxygen isotope tracer technology and the MixSIAR model were used to qualitatively and quantitatively determine the sources of surface water nitrate and their contribution rates. The results showed that there were significant spatial and temporal differences in nitrate concentrations in the Wuding River Basin. In terms of time, the mean concentration of NO-3-N in surface water in the wet season was higher than that in the flat-water period; spatially, the mean concentration of NO-3-N in the downstream surface water was higher than that in the upstream. The spatial and temporal differences in surface water nitrate concentrations were mainly affected by rainfall runoff, soil types, and land use types. The main sources of nitrates in the surface water of the Wuding River Basin during the wet season were domestic sewage, manure, chemical fertilizers, and soil organic nitrogen, whose contribution rates were 43.3%, 27.6%, and 22.1%, respectively, and the contribution rate of precipitation was only 7.0%. There were differences in the contribution rate of nitrate pollution sources in surface water of different river sections. The contribution rate of soil nitrogen in the upstream was significantly higher than that in the downstream, which was 26.5%. The contribution rate of domestic sewage and manure in the downstream was significantly higher than that in the upstream, which was 48.9%. To provide a basis for the analysis of nitrate sources and pollution control in Wuding River and even rivers in arid and semi-arid regions.

Modeling and minimization for thermal stress birefringence of an optical voltage transducer.

The thermal stress birefringence (TSB) is a big issue that destroys the sensing stability of the optical voltage transducer (OVT), and the existing research on the theoretical modeling and solution are not good enough to handle it. This paper presents a mathematical model of the TSB based on the photo-elastic effect, and then it is quantitatively calculated through the multiphysics coupling simulation. It shows that the asymmetric radial stresses in the electro-optic crystal are the root cause for the TSB, which results in a phase delay greater than 3.153°. On this basis, a method for TSB minimization to use the polyurethane buffer layer to enwrap around the crystal is proposed, which eliminates the random radial stress and improves the symmetry of stress distribution. Finally, the effectiveness of the proposed method is verified by simulation and experiment.

Plasma Exosomal CXCL7 is a Potential Biomarker for Lung Adenocarcinoma.

BACKGROUND: Lung cancer is a leading cause of cancer-related death, with lung adenocarcinoma (LUAD) representing the most common subtype. Recently, exosome-based biomarkers have provided new diagnostic approaches for malignancies. METHODS: The differential expression profile of plasma exosomal mRNA was established by high-throughput sequencing, and the expression and diagnostic value of plasma exosomal CXCL7 mRNA and protein in LUAD were studied to evaluate their diagnostic value as tumor biomarkers. RESULTS: The expression of plasma exosomal CXCL7 mRNA in patients with LUAD was significantly increased (p < 0.01), which had no significant correlation with age, gender, and stage. ROC was used to evaluate the diagnostic value of plasma exosomal CXCL7 mRNA in LUAD patients with AUC = 0.7171. Further analysis signified that the CXCL7 protein of plasma exosomes in LUAD patients was overexpressed, and it was positively correlated with TNM stage and age. The diagnostic value of plasma exosomal CXCL7 in LUAD is better than serum CEA, with an AUC of 0.785, which has higher sensitivity and specificity. CONCLUSIONS: This research suggests that plasma exosomal CXCL7 may become an effective biomarker for early diagnosis of LUAD.

Concentrated extract of Prunus mume fruit exerts dual effects in 3T3-L1 adipocytes by inhibiting adipogenesis and inducing beiging/browning.

BACKGROUND: The fruit Prunus mume has beneficial effects in the treatment of obesity and metabolic syndrome. However, its mechanism of action is unclear. OBJECTIVE: We assessed the effect of a concentrated water extract of P. mume fruit (CEPM) on adipogenesis and beiging/browning in 3T3-L1 cells. METHODS: The cell viability was determined by MTT assay. Lipid accumulation was assessed with Oil Red O (ORO) staining under different concentrations of CEPM. The effects of CEPM treatment during differentiation on beiging/browning and mitochondrial biogenesis in 3T3-L1 cells were investigated. RESULTS: CEPM treatment suppressed differentiation and decreased lipid accumulation by downregulating the expression of key adipogenic genes, including PPARγ, C/EBPα, SREBP-1c, FAS, and perilipin A. In contrast, CEPM treatment increased the mitochondrial DNA (mtDNA) content and mRNA levels of mitochondrial biogenesis genes, including NAMPT, Nrf1, Nrf2, and CPT1α, and reduced reactive oxygen species levels. Importantly, CEPM increased the expression of brown/beige hallmark genes (Pgc-1α, Ucp1, Cidea, Cox7α1, Cox8b, Cd137, and Pdk-4), as well as proteins (UCP1, PGC-1α, NRF1, TBX1, and CPT1α). The high-performance liquid chromatography (HPLC) analysis reveals that CEPM contains mumefural, naringin, 5-HMF, citric acid, caffeic acid, and hesperidin. CONCLUSION: The first evidence we provided showed that CEPM has a dual role in 3T3-L1 cells inhibiting adipogenesis and promoting beiging/browning, and hence, could be a potential agent in the fight against obesity.

SNX-3 mediates retromer-independent tubular endosomal recycling by opposing EEA-1-facilitated trafficking.

Early endosomes are the sorting hub on the endocytic pathway, wherein sorting nexins (SNXs) play important roles for formation of the distinct membranous microdomains with different sorting functions. Tubular endosomes mediate the recycling of clathrin-independent endocytic (CIE) cargoes back toward the plasma membrane. However, the molecular mechanism underlying the tubule formation is still poorly understood. Here we screened the effect on the ARF-6-associated CIE recycling endosomal tubules for all the SNX members in Caenorhabditis elegans (C. elegans). We identified SNX-3 as an essential factor for generation of the recycling tubules. The loss of SNX-3 abolishes the interconnected tubules in the intestine of C. elegans. Consequently, the surface and total protein levels of the recycling CIE protein hTAC are strongly decreased. Unexpectedly, depletion of the retromer components VPS-26/-29/-35 has no similar effect, implying that the retromer trimer is dispensable in this process. We determined that hTAC is captured by the ESCRT complex and transported into the lysosome for rapid degradation in snx-3 mutants. Interestingly, EEA-1 is increasingly recruited on early endosomes and localized to the hTAC-containing structures in snx-3 mutant intestines. We also showed that SNX3 and EEA1 compete with each other for binding to phosphatidylinositol-3-phosphate enriching early endosomes in Hela cells. Our data demonstrate for the first time that PX domain-only C. elegans SNX-3 organizes the tubular endosomes for efficient recycling and retrieves the CIE cargo away from the maturing sorting endosomes by competing with EEA-1 for binding to the early endosomes. However, our results call into question how SNX-3 couples the cargo capture and membrane remodeling in the absence of the retromer trimer complex.

WIP-1 and DBN-1 promote scission of endocytic vesicles by bridging actin and Dynamin-1 in the C. elegans intestine.

There has been a consensus that actin plays an important role in scission of the clathrin-coated pits (CCPs) together with large GTPases of the dynamin family in metazoan cells. However, the recruitment, regulation and functional interdependence of actin and dynamin during this process remain inadequately understood. Here, based on small-scale screening and in vivo live-imaging techniques, we identified a novel set of molecules underlying CCP scission in the multicellular organism Caenorhabditis elegans We found that loss of Wiskott-Aldrich syndrome protein (WASP)-interacting protein (WIP-1) impaired CCP scission in a manner that is independent of the C. elegans homolog of WASP/N-WASP (WSP-1) and is mediated by direct binding to G-actin. Moreover, the cortactin-binding domain of WIP-1 serves as the binding interface for DBN-1 (also known in other organisms as Abp1), another actin-binding protein. We demonstrate that the interaction between DBN-1 and F-actin is essential for Dynamin-1 (DYN-1) recruitment at endocytic sites. In addition, the recycling regulator RME-1, a homolog of mammalian Eps15 homology (EH) domain-containing proteins, is increasingly recruited at the arrested endocytic intermediates induced by F-actin loss or DYN-1 inactivation, which further stabilizes the tubular endocytic intermediates. Our study provides new insights into the molecular network underlying F-actin participation in the scission of CCPs.This article has an associated First Person interview with the first author of the paper.

Relationship between the benefits of paraspinal mapping and diffusion tensor imaging and the increase of decompression levels determined by conventional magnetic resonance imaging in degenerative lumbar spinal stenosis.

BACKGROUND: In lumbar spinal stenosis (LSS), at most times, several levels are impaired and selecting the correct level remains a common problem for surgeons, as surgery remains invasive, and extended laminectomy may lead to secondary surgical complications. Therefore, helping to select the correct level may be useful for surgeons. The use of diffuse tensor imaging (DTI) and paraspinal mapping (PM) in addition to conventional magnetic resonance imaging (MRI) may be helpful (Chen et al., J Orthop Surg Res 11:47, 2016). However, with decompression levels determined by conventional magnetic resonance imaging (MRI) increasing, whether the benefits of reducing decompression level of conventional MRI + (DTI or PM) will be more obvious is unknown. METHODS: Reduced surgical levels that were different between levels determined by conventional MRI + (DTI or PM) and conventional MRI + neurogenic examination (NE) between groups were compared. Treatment outcome measures were performed at 2 weeks, 3 months, 6 months, and 12 months postoperatively. RESULTS: The reduced levels of three groups showed no statistically significant differences between each other except for two levels and four levels (two levels/three levels, p = 0.085; two levels/four levels, p = 0.039; three levels/ four levels, p = 0.506, respectively). CONCLUSIONS: With surgical levels determined by conventional MRI increasing, the benefits of DTI and PM will be uncertainly more obvious.

The Influence of the Global Gene Expression Shift on Downstream Analyses.

The assumption that total abundance of RNAs in a cell is roughly the same in different cells is underlying most studies based on gene expression analyses. But experiments have shown that changes in the expression of some master regulators such as c-MYC can cause global shift in the expression of almost all genes in some cell types like cancers. Such shift will violate this assumption and can cause wrong or biased conclusions for standard data analysis practices, such as detection of differentially expressed (DE) genes and molecular classification of tumors based on gene expression. Most existing gene expression data were generated without considering this possibility, and are therefore at the risk of having produced unreliable results if such global shift effect exists in the data. To evaluate this risk, we conducted a systematic study on the possible influence of the global gene expression shift effect on differential expression analysis and on molecular classification analysis. We collected data with known global shift effect and also generated data to simulate different situations of the effect based on a wide collection of real gene expression data, and conducted comparative studies on representative existing methods. We observed that some DE analysis methods are more tolerant to the global shift while others are very sensitive to it. Classification accuracy is not sensitive to the shift and actually can benefit from it, but genes selected for the classification can be greatly affected.

Reducing surgical levels by paraspinal mapping and diffusion tensor imaging techniques in lumbar spinal stenosis.

BACKGROUND: Correlating symptoms and physical examination findings with surgical levels based on common imaging results is not reliable. In patients who have no concordance between radiological and clinical symptoms, the surgical levels determined by conventional magnetic resonance imaging (MRI) and neurogenic examination (NE) may lead to a more extensive surgery and significant complications. We aimed to confirm that whether the use of diffusion tensor imaging (DTI) and paraspinal mapping (PM) techniques can further prevent the occurrence of false positives with conventional MRI, distinguish which are clinically relevant from levels of cauda equina and/or nerve root lesions based on MRI, and determine and reduce the decompression levels of lumbar spinal stenosis than MRI + NE, while ensuring or improving surgical outcomes. METHODS: We compared the data between patients who underwent MRI + (PM or DTI) and patients who underwent conventional MRI + NE to determine levels of decompression for the treatment of lumbar spinal stenosis. Outcome measures were assessed at 2 weeks, 3 months, 6 months, and 12 months postoperatively. RESULTS: One hundred fourteen patients (59 in the control group, 54 in the experimental group) underwent decompression. The levels of decompression determined by MRI + (PM or DTI) in the experimental group were significantly less than that determined by MRI + NE in the control group (p = 0.000). The surgical time, blood loss, and surgical transfusion were significantly less in the experimental group (p = 0.001, p = 0.011, p = 0.001, respectively). There were no differences in improvement of the visual analog scale back and leg pain (VAS-BP, VAS-LP) scores and Oswestry Disability Index (ODI) scores at 2 weeks, 3 months, 6 months, and 12 months after operation between the experimental and control groups. CONCLUSIONS: MRI + (PM or DTI) showed clear benefits in determining decompression levels of lumbar spinal stenosis than MRI + NE. In patients with lumbar spinal stenosis, the use of PM and DTI techniques reduces decompression levels and increases safety and benefits of surgery.

[Isolation and degrading characters of chlorpyrifos degrading bacteria XZ-3].

A strain of bacterium XZ-3 capable of highly degrading chlorpyrifos was screened from the soil sample collected from a pesticide plant after taming and enrichment. Based on analysis of phenotype, physiological and biochemical characters and 16S rDNA, XZ-3 was identified as Arthrobacter sp.. The effects of carbon source, pH, temperature and chlorpyrifos concentration on degradation were determined. The growth of bacteria in culture media were measured by visible absorption spectrophotometry under 400 nm. The residual chlorpyrifos in culture media was extracted with an equal volume of petroleum ether, and then determined by ultra-violet spectrophotometry. The results showed that the degradation rate of chlorpyrifos by XZ-3 was 86.8% in 24 h. The biodegradation rates were the highest when the additional carbon source was 0.3%, pH value was 9, chlorpyrifos concentration was 100 mg x L(-1), and cultivated temperature was 30 degrees C. The growth of bacteria increased with carbon source concentration, and was higher with pH from 8.0 to 10.0, and the highest when temperature was 30 degrees C, and chlorpyrifos concentration was 800 mg x L(-1). The strain could survive when chlorpyrifos concentration was 1000 mg x L(-1) and the removed amount of chlorpyrifos increased with chlorpyrifos concentration. The optimal conditions were proposed, which could provide theoretic basis for prevention and control of pesticides pollution.