16 research outputs found

    Comparison of Bacterial Communities in Two Partial Nitrification Systems for High-ammonia Wastewater and Sewage Treatment

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    ABSTRACT Partial nitritation is an important part of the biological nitrogen removal processes; it saves half of the aeration energy, since only half of NH 4 + -N need to be oxidized to nitrite. The performance of the process was determined by the microbial community structure. In this study, we measured the microbial diversity in terms of the quantity of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) that were present. The results revealed that the amount of aerobic bacteria did not change significantly in high-ammonia wastewater, but decreased significantly with running time in sewage. The abundance of AOB and NOB in high-ammonia wastewater ranged from 1.23 × 10 7 to 8.95 × 10

    Functional polymorphisms of the APOA1/C3/A4/A5-ZPR1-BUD13 gene cluster are associated with dyslipidemia in a sex-specific pattern

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    Background Dyslipidemia contributes to the risk of many diseases, including stroke, cardiovascular disease and metabolic-related diseases. Previous studies have indicated that single nucleotide polymorphisms (SNPs) are associated with different levels of serum lipid. Therefore, this study explored the relationship between the APOA1/C3/A4/A5-ZPR1-BUD13 gene cluster gene polymorphisms and dyslipidemia in the total sample population and stratified by genders in a northeast Chinese population. Methods A total of 3,850 participants from Jilin Province, China, were enrolled in our study, and their serum lipid levels were measured. Six functional SNPs (APOA1 rs5072, APOC3 rs5128, APOA4 rs5104, APOA5 rs651821, ZPR1 rs2075294 and BUD13 rs10488698) were genotyped using polymerase chain reaction and MALDI-TOF-MS. Logistic regression analysis was performed to explore the relationship of APOA1/C3/A4/A5-ZPR1-BUD13 gene cluster gene polymorphisms with dyslipidemia. Linkage disequilibrium and haplotype analyses were performed with the SNPStats program and Haploview software. Results All SNPs conformed to Hardy–Weinberg equilibrium. Logistic regression analysis revealed that rs5072, rs5128 and rs651821 were associated with hypertriglyceridemia, rs5104 and rs651821 were associated with low-HDL cholesterolemia in overall group. rs651821 was associated with hypertriglyceridemia and low-HDL cholesterolemia in both the male and female group. However, among females, rs5072 was observed to be associated with hypertriglyceridemia. Haplotype analysis showed that haplotypes TGCCGC and CAGCGC were associated with dyslipidemia in the overall, male and female groups. Conclusion SNPs in the APOA1/C3/A4/A5-ZPR1-BUD13 gene cluster were associated with dyslipidemia. Furthermore, the association of APOA1 rs5072 in this gene cluster with dyslipidemia differed between genders; thus, additional studies are needed to confirm this conclusion, and the mechanisms underlying these results warrant further exploration

    Autonomous Planning and Robust Control for Wheeled Mobile Robot With Slippage Disturbances Based on Differential Flat

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    Abstract This paper proposes a wheeled mobile robot (WMR) robust control scheme. The feasible strategy is developed to achieve an efficient and robust autonomous mobile robot motion. To realize kinematic autonomous planning and control of the WMR, a novel controller is designed based on control Lyapunov function. This part can be divided into the following two aspects: 1) considering the nonholonomic constraints in the autonomous mobile robot trajectory tracking, a dynamic feedback‐linearization is adopted by utilizing differential flatness‐based integrated control framework to achieve full‐state controllability; 2) to compensate the structured uncertainties and slippage disturbances related to the robot kinematic model, a robust controller is designed based on control Lyapunov function with quadratic programming. Such a strategy can achieve autonomous motion even with unknown slippage disturbances subject to various constraints. Moreover, the sufficient condition is also analyzed to ensure the WMR system exponential stability. The effectiveness and performance of the proposed method are verified by numerical simulation

    A Comparative Study of Different Quality Oil Shales Developed in the Middle Jurassic Shimengou Formation, Yuqia Area, Northern Qaidam Basin, China

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    Oil shales are developed in the Shale Member of the Middle Jurassic Shimengou Formation in the Qaidam Basin, China. The oil shales can be classified into three quality groups (low-, medium-, and high-quality oil shales) through a comprehensive analysis protocol that includes Rock-Eval pyrolysis, total organic carbon (TOC) content, proximate analysis, gas chromatography-mass spectrometry (GC-MS), X-ray diffraction (XRD), major and trace element analyses, and maceral analysis. The low-quality oil shales mainly contain type II1 kerogen, the medium-quality oil shales mainly contain type I-II1 kerogen, and the high-quality oil shales mainly contain type I kerogen. All are immature to early thermally mature. The oil yield of the oil shales is directly related to their quality and are positively correlated with TOC content and calorific value. All studied samples were deposited under anaerobic conditions but in different paleoenvironments. The low-quality oil shales were mainly deposited in fresh-water environments, whereas the high-quality oil shales were usually developed in highly saline and reducing environments. Salinity stratification and evidence of algal blooms that are conducive to organic matter enrichment were identified in both medium- and high-quality oil shales, the latter having the highest paleoproductivity and the best preservation conditions. In summary, shale quality is controlled by a combination of factors, including algal abundance, preservation conditions, the existence of algal blooms and salinity stratification, and paleoproductivity. This study reveals how these different factors affect the quality of oil shales, which might provide an in-depth explanation for the formation process of lacustrine oil shales

    Genome-Wide Identification and Expression Analysis of HD-ZIP I Gene Subfamily in Nicotiana tabacum

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    The homeodomain-leucine zipper (HD-Zip) gene family, whose members play vital roles in plant growth and development, and participate in responding to various stresses, is an important class of transcription factors currently only found in plants. Although the HD-Zip gene family, especially the HD-Zip I subfamily, has been extensively studied in many plant species, the systematic report on HD-Zip I subfamily in cultivated tobacco (Nicotiana tabacum) is lacking. In this study, 39 HD-Zip I genes were systematically identified in N. tabacum (Nt). Interestingly, that 64.5% of the 31 genes with definite chromosome location information were found to originate from N. tomentosoformis, one of the two ancestral species of allotetraploid N. tabacum. Phylogenetic analysis divided the NtHD-Zip I subfamily into eight clades. Analysis of gene structures showed that NtHD-Zip I proteins contained conserved homeodomain and leucine-zipper domains. Three-dimensional structure analysis revealed that most NtHD-Zip I proteins in each clade, except for those in clade η, share a similar structure to their counterparts in Arabidopsis. Prediction of cis-regulatory elements showed that a number of elements responding to abscisic acid and different abiotic stresses, including low temperature, drought, and salinity, existed in the promoter region of NtHD-Zip I genes. The prediction of Arabidopsis ortholog-based protein–protein interaction network implied that NtHD-Zip I proteins have complex connections. The expression profile of these genes showed that different NtHD-Zip I genes were highly expressed in different tissues and could respond to abscisic acid and low-temperature treatments. Our study provides insights into the evolution and expression patterns of NtHD-Zip I genes in N. tabacum and will be useful for further functional characterization of NtHD-Zip I genes in the future

    Diverse sedimentary conditions during deposition Of coal and oil shale from the Meihe Basin (Eocene, NE China)

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    The Meihe Basin in northeastern China is a normal-fault-controlled basin filled with Eocene nonmarine deposits, the sediments assigned to the Meihe Formation. Sediment grain-sizes, core study, well-log analysis and micropetrographic study combined with sedimentary facies analysis indicate that the main sedimentary facies of the Meihe Basin represent fan-delta, lake, and turbidite deposits. Thick coal seams that are mainly distributed in the eastern part of the studied area were deposited in the swamp facies of the Lower Coal-Bearing Member. Oil shale was mainly deposited in the deep lake represented by the Mudstone Member, and is mainly distributed in the southern part of the studied area. In the Lower Coal-Bearing Member, organic-rich sediments are characterized by TOC content between 0.6 wt.% and 43.1 wt.%and contain Type II and III kerogen. The thick coal seams are the result of high landplant productivity and good preservation conditions. Thin coal seams in the fan-delta plain resulted from the migration and erosion of the fan-delta channel. In the shallow lake and fan-delta front, limited productivity coupled with dilution by inorganic matter resulted in lower organic-matter content in theMudstoneMember. Oil shale and mudstone rich in organic matter were deposited in a deep lake with an average TOC content of 3.4 wt.%. The origin of the organic matter was mainly algae and aquatic plants mixed with land plants. The improved preservation conditions and high bioproductivity in this environment resulted in three oil-shale layers in the lower part of this sedimentary succession. Three coal-bearing and oil-shale-bearing fault basins lie adjacent to the Dunhua-Mishan Fault zone, among which the Fushun Basin is located in the southwest, the Meihe Basin is in themiddle, and theHuadian Basin is in the southeast. From the Fushun Basin to the Huadian Basin, the oil shale and coal seams have distinct sedimentation characters laterally. Vertically in each basin, the organic-matter sources all have the same variation trend from land plants to land plants mixed with algae to algae then to algae mixed with land plants, and the TOC content also shows a similar trend from high to medium-high then to low in each basin

    Highly Selective and Humidity-Resistant Triethylamine Sensors Based on Pt and Cr<sub>2</sub>O<sub>3</sub> Nanoparticles

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    A triethylamine gas sensor with humidity resistance, high selectivity, and high response is designed. Chromium oxide particles were prepared by heating them in a water bath at 80 °C. Pt/Cr2O3 nanoparticles were obtained by sodium borohydride reduction. The structure morphology of nanoparticles was characterized by some methods. The gas response test results showed that the modification of Pt improved the response value and selectivity of Cr2O3 to triethylamine. It was found that Cr2O3–2Pt nanoparticles had the best performance, and at the optimum operating temperature of 160 °C, its response value reached 200, 68 times that of Cr2O3 (S = 2.95). In addition, the modification of Pt made Cr2O3–2Pt nanoparticles had a wide range of humidity applications. The mechanism of gas response is explained by using the Schottky barrier and hole accumulation layer model of Pt and Cr2O3 contact and energy band theory

    The Symptoms and Medications of Patients with Inflammatory Bowel Disease in Hubei Province after COVID-19 Epidemic

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    Objectives. The COVID-19 epidemic triggered by coronavirus SARS-CoV-2 is rapidly spreading around the globe. This study is aimed at finding out the suspected or confirmed SARS-CoV-2 infection in patients with inflammatory bowel disease (IBD) in Hubei province, China. We also investigated symptoms, medications, life quality, and psychological issues of IBD patients under the ongoing pandemic. Methods. We conducted a self-reported questionnaire survey via an online survey platform. SARS-CoV-2 infection-related data was collected from IBD patients. The status quo of medications and symptoms of the subjects were investigated. Life quality, depression, and anxiety were measured by clinical questionnaires and rated on scoring systems. Results. A total of 204 IBD patients from Hubei province were included in this study. No suspected or confirmed SARS-CoV-2 infection case was found in this study. As a result of city shutdown, two-thirds of the patients (138/204) in our series reported difficulty in accessing medicines and nearly half of them (73/138) had to discontinue medications. Apart from gastrointestinal symptoms, systemic symptoms were common while respiratory symptoms were rare in the cohort. Though their quality of life was not significantly lowered, depression and anxiety were problems that seriously affected them during the COVID-19 epidemic. Conclusions. Inaccessibility to medications is a serious problem for IBD patients after city shutdown. Efforts have to be made to address the problems of drug withdrawal and psychological issues that IBD patients suffer from during the COVID-19 outbreak
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