293 research outputs found

    On some classes of projectively flat Finsler metrics with constant flag curvature

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    Abstract(#br)In this paper, we give the equivalent PDEs for projectively flat Finsler metrics with constant flag curvature defined by a Euclidean metric and two 1-forms. Furthermore, we construct some classes of new projectively flat Finsler metrics with constant flag curvature by solving these equivalent PDEs

    Evaluating the effect of lactic acid bacteria fermentation on quality, aroma, and metabolites of chickpea milk

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    Legumes are an attractive choice for developing new products since their health benefits. Fermentation can effectively improve the quality of soymilk. This study evaluated the impact of Lactobacillus plantarum fermentation on the physicochemical parameters, vitamins, organic acids, aroma substances, and metabolites of chickpea milk. The lactic acid bacteria (LAB) fermentation improved the color, antioxidant properties, total phenolic content, total flavonoid content, lactic acid content, and vitamin B6 content of raw juice. In total, 77 aroma substances were identified in chickpea milk by headspace solid-phase microextraction with gas chromatography/mass spectrometry (HS-SPME-GC-MS); 43 of the 77 aroma substances increased after the LAB fermentation with a significant decrease in beany flavor content (p < 0.05), improving the flavor of the soymilk product. Also, a total of 218 metabolites were determined in chickpea milk using non-targeted metabolomics techniques, including 51 differentially metabolites (28 up-regulated and 23 down-regulated; p < 0.05). These metabolites participated in multiple metabolic pathways during the LAB fermentation, ultimately improving the functional and antioxidant properties of fermented soymilk. Overall, LAB fermentation can improve the flavor, nutritional, and functional value of chickpea milk accelerating its consumer acceptance and development as an animal milk alternative

    A Novel Bayesian Framework Infers Driver Activation States and Reveals Pathway-Oriented Molecular Subtypes in Head and Neck Cancer

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    Head and neck squamous cell cancer (HNSCC) is an aggressive cancer resulting from heterogeneous causes. To reveal the underlying drivers and signaling mechanisms of different HNSCC tumors, we developed a novel Bayesian framework to identify drivers of individual tumors and infer the states of driver proteins in cellular signaling system in HNSCC tumors. First, we systematically identify causal relationships between somatic genome alterations (SGAs) and differentially expressed genes (DEGs) for each TCGA HNSCC tumor using the tumor-specific causal inference (TCI) model. Then, we generalize the most statistically significant driver SGAs and their regulated DEGs in TCGA HNSCC cohort. Finally, we develop machine learning models that combine genomic and transcriptomic data to infer the protein functional activation states of driver SGAs in tumors, which enable us to represent a tumor in the space of cellular signaling systems. We discovered four mechanism-oriented subtypes of HNSCC, which show distinguished patterns of activation state of HNSCC driver proteins, and importantly, this subtyping is orthogonal to previously reported transcriptomic-based molecular subtyping of HNSCC. Further, our analysis revealed driver proteins that are likely involved in oncogenic processes induced by HPV infection, even though they are not perturbed by genomic alterations in HPV+ tumors

    Upwelling velocity and ventilation in the western South China Sea deduced from CFC-12 and SF6 observations

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    This study presents observations of the transient tracers CFC-12 and SF6 in the western South China Sea during the fall of 2015. A CFC-12 maximum was discovered in the western South China Sea at the subsurface layer (150–200 m), which could be traced back to the North Pacific Tropical Water. The transit time distribution approach was used to estimate the ventilation time in this area. The constrained Δ /Γ ratio of 0.5 was obtained using CFC-12/SF6 tracer pair. This ratio is lower than the empirical unit ratio of one as used for previous estimates. Waters in the northern region of the western South China Sea appear younger than waters in the southern region. The water mass corresponding to the salinity minimum has a mean age of ∼67 ± 16 years along the 15º N line (marked by the red dashed rectangle in Fig. 1), which increases to ∼76 ± 18 years along the 10º N line (blue dashed rectangle, Fig. 1). The higher mean ages indicate that the intermediate water was ventilated from the North Pacific, which is far distant from the South China Sea. The column inventory of Cant is ∼31.3 mol C m–2. Upwelling velocities of up to ∼55 × 10–5 m s–1 was computed using the tracer data, indicating that tracer-free water as yet not influenced by human perturbation could be carried to the upper layer by upwelling. Using the transit time distribution derived mean age with transient tracers provides a possible way to determine the ventilation time scale for the study area

    Chitosan treatment reduces softening and chilling injury in cold-stored Hami melon by regulating starch and sucrose metabolism

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    Cold-stored Hami melon is susceptible to chilling injury, resulting in quality deterioration and reduced sales. Pre-storage treatment with chitosan reduces fruit softening and chilling injury in melon; however, the underlying mechanism remains unclear. In this study, Gold Queen Hami melons were treated with 1.5% chitosan solution for 10 min before cold storage at 3°C and then the effect of chitosan was examined on fruit firmness, weight loss, chilling injury, soluble solid content (SSC), pectin, and soluble sugar contents of melon fruit. Also, the enzyme activities and gene expressions related to fruit softening and starch and sucrose metabolism were investigated. Chitosan treatment reduced the fruit softening and chilling injury, maintained the high levels of starch and sucrose contents, and regulated the enzyme activities and gene expressions related to starch and sucrose metabolism. Fruit firmness was significantly positively correlated with sucrose and starch contents. Altogether, we uncovered the potential mechanism of chitosan coating mitigating melon softening and chilling injury through the regulation of starch and sucrose metabolism

    Operating Conditions of Hollow Fiber Supported Liquid Membrane for Phenol Extraction from Coal Gasification Wastewater

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    The extraction and recycling of phenol from high concentration coal gasification wastewater has been studied using polypropylene (PP) hollow fiber membrane and polyvinylidene fluoride (PVDF) hollow fiber membrane as liquid membrane support, the mixture of tributyl phosphate (TBP) and kerosene as liquid membrane phase, and sodium hydroxide as stripping agent in the process of extraction. The experiments investigated the effect of the operating conditions of the hollow fiber supported liquid membrane, such as aqueous phase temperature and the connection forms of membrane modules, on the extraction efficiency of phenol from high concentration coal gasification wastewater. The conclusions obtained from lab scale experiments provided guidance for scale-up experiments. So, in the scale-up experiments, three membrane modules connected in parallel, then three membrane modules connected in series were used to increase the treatment capacity and improve the treatment effect, under the operating conditions of wastewater temperature 20 ËšC, PH 7.5~8.1, flow rate 100 L/h and the concentration of stripping phase 0.1 mol/L, stripping phase flow rate 50 L/h, the extraction efficiency of the PP-TBP supported liquid membrane system was 87.02% and the phenol concentration of effluent was 218.14mg/L. And the phenol concentration of effluent met the requirements of further biodegradation treatment

    Analysis of Fungal Community Structure and Flavor Quality of High-temperature Daqu from Xiangyang, China

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    The fungal community structure and flavor quality of white, yellow and black high-temperature Daqu from company A in Xiangyang, China were analyzed using MiSeq high-throughput sequencing and electronic nose technology. The sequencing results showed no significant differences in the α-diversity or β-diversity of fungal community among different colored Daqu (P > 0.05); the dominant fungal genera belonged to Ascomycota including Thermomyces (36.50%), Thermoascus (27.15%), Saccharomycopsis (9.23%) and Dipodascus (1.19%), and Mucoromycota including Aspergillus (9.36%), Rhizopus (1.44%) and Rhizomucor (1.03%). The electronic nose exhibited high sensor responses to volatile organic sulfides, terpenoids, hydroxides and ethanol and low sensor responses to aromatic substances in high-temperature Daqu; the Mann-Whitney test revealed significantly higher sensor responses to aromatic substances (P < 0.01) and lower sensor responses to the other aroma components (P < 0.05) in yellow than black Daqu. In addition, based on the fungal sequence data from the MG-RAST database for three different colored high-temperature Daqu produced by company B, comparative analysis of the fungal community structure of high-temperature Daqu produced by companies A and B was carried out. It was found that there were highly significant differences (P < 0.01) in the α-diversity and β-diversity of fungal community between Daqu produced by the two companies, and the results of cluster analysis showed that the Mahalanobis distance between the different colored high-temperature Daqu from the same company was closer. Finally, in this study, four strains of S. fibuligera were isolated from high-temperature Daqu produced by company A by traditional pure culture method. In conclusion, there was a significant difference between the fungal communities of high-temperature Daqu produced by companies A and B, which was greater than the difference between different colored high-temperature Daqu produced by the same company

    Genetic Variants in KIR/HLA-C Genes Are Associated With the Susceptibility to HCV Infection in a High-Risk Chinese Population

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    BackgroundKIR/HLA-C signaling pathway influences the innate immune response which is the first defense to hepatitis C virus (HCV) infection. The aim of this study was to determine the association between the genetic polymorphisms of KIR/HLA-C genes and the outcomes of HCV infection in a high-risk Chinese population.MethodsIn this case-control study, four single nucleotide polymorphisms (SNPs) of KIR/HLA-C genes (KIR2DS4/KIR2DS1/KIR2DL1 rs35440472, HLA-C rs2308557, HLA-C rs1130838, and HLA-C rs2524094) were genotyped by TaqMan assay among drug users and hemodialysis (HD) patients including 1,378 uninfected control cases, 307 subjects with spontaneous viral clearance, and 217 patients with persistent HCV infection. Bioinformatics analysis was used to functionally annotate the SNPs.ResultsAfter logistic regression analysis, the rs35440472-A and rs1130838-A alleles were found to be associated with a significantly elevated risk of HCV infection (OR = 1.562, 95% CI: 1.229–1.987, P &lt; 0.001; OR = 2.134, 95% CI: 1.180–3.858, P = 0.012, respectively), which remained significant after Bonferroni correction (0.05/4). The combined effect of their risk alleles and risk genotypes (rs35440472-AA and rs1130838-AA) were linked to the increased risk of HCV infection in a locus-dosage manner (all Ptrend &lt; 0.001). Based on the SNPinfo web server, rs35440472 was predicted to be a transcription factor binding site (TFBS) while rs1130838 was predicted to have a splicing (ESE or ESS) function.ConclusionKIR2DS4/KIR2DS1/KIR2DL1 rs35440472-A and HLA-C rs1130838-A variants are associated with increased susceptibility to HCV infection in a high-risk Chinese population

    Serum level of S100A8/A9 as a biomarker for establishing the diagnosis and severity of community-acquired pneumonia in children

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    BackgroundS100A8/A9, which is a member of S100 proteins, may be involved in the pathophysiology of Community-acquired pneumonia (CAP) that seriously threatens children’s health. However, circulating markers to assess the severity of pneumonia in children are yet to be explored. Therefore, we aimed to investigate the diagnostic performance of serum S100A8/A9 level in determining the severity of CAP in children.MethodsIn this prospective and observational study, we recruited 195 in-hospital children diagnosed with CAP. In comparison, 63 healthy children (HC) and 58 children with non-infectious pneumonia (pneumonitis) were included as control groups. Demographic and clinical data were collected. Serum S100A8/A9 levels, serum pro-calcitonin concentrations, and blood leucocyte counts were quantified.ResultsThe serum S100A8/A9 levels in patients with CAP was 1.59 ± 1.32 ng/mL, which was approximately five and two times higher than those in healthy controls and those in children with pneumonitis, respectively. Serum S100A8/A9 was elevated parallelly with the clinical pulmonary infection score. The sensitivity, specificity, and Youden’s index of S100A8/A9 ≥1.25 ng/mL for predicting the severity of CAP in children was optimal. The area under the receiver operating characteristic curve of S100A8/A9 was the highest among the indices used to evaluate severity.ConclusionsS100A8/A9 may serve as a biomarker for predicting the severity of the condition in children with CAP and establishing treatment grading
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