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Relative permeability of polymer flooding plays a very important role in oil field development. This paper aimed to measure and calculate the relative permeability curves of polymer flooding more accurately. First, viscosity variation law of polymer in porous media was studied. Rock particles of different diameters and cementing agent were used to make artificial cores and hydrophobically associating polymer solutions were prepared for experiments. Polymer solutions were injected into the cores filled with crude oil and irreducible water. In the process of polymer flooding, produced fluid was collected at different water saturations and locations of the core. Polymer solutions were separated and their viscosities were measured. With the experimental data, the viscosity variation rule of polymer transporting in porous media was explored. The result indicates that the viscosity retention rate of polymer solutions transporting in porous media has power function relationship with the water saturation and the dimensionless distance from the core inlet. Finally, the relative permeability curves of polymer flooding were measured by unsteady state method and the viscosity variation rule was applied to the calculation of the relative permeability curves.
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Polímeros , Agua , Permeabilidad , Porosidad , ViscosidadRESUMEN
Metabolite profiling in anaerobic alkane biodegradation plays an important role in revealing activation mechanisms. Apart from alkylsuccinates, which are considered to be the usual biomarkers via fumarate addition, the downstream metabolites of C-skeleton rearrangement can also be regarded as biomarkers. However, it is difficult to detect intermediate metabolites in both environmental samples and enrichment cultures, resulting in lacking direct evidence to prove the occurrence of fumarate addition pathway. In this work, a synthetic method of rearrangement metabolites was established. Four compounds, namely, propylmalonic acid, 2-(2-methylbutyl)malonic acid, 2-(2-methylpentyl)malonic acid and 2-(2-methyloctyl)malonic acid, were synthesized and determined by four derivatization approaches. Besides, their mass spectra were obtained. Four characteristic ions were observed at m/z 133 + 14n, 160 + 28n, 173 + 28n and [M - (45 + 14n)]+ (n = 0 and 2 for ethyl and n-butyl esters, respectively). For methyl esterification, mass spectral features were m/z 132, 145 and [M - 31]+, while for silylation, fragments were m/z 73, 147, 217, 248, 261 and [M - 15]+. These data provide basis on identification of potential rearrangement metabolites in anaerobic alkane biodegradation via fumarate addition.
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Alcanos/metabolismo , Fumaratos/metabolismo , Malonatos/metabolismo , Alcanos/química , Anaerobiosis , Fumaratos/química , Malonatos/química , Espectrometría de MasasRESUMEN
The construction of pseudogemini surfactants based on noncovalent interactions (such as electrostatic interaction and π-π stacking) was a powerful method to assemble well-defined aggregates in aqueous solution. The mixtures of butane-1,4-bis(methylimidazolium bromide) ([mim-C4-mim]Br2) and positional isomers of sodium dodecyl benzene sulfonate (SDBS-0,11 or SDBS-3,8) in a molar ratio of 1:2 were studied to characterize the effect of straight and branched alkyl chains on the aggregation behavior of pseudogemini surfactants. Spontaneous phase transition from micelles to vesicles was formed by these two kinds of complexes. Interestingly, a densely stacked onion-like structure (multilamellar vesicles) with more than one dozen layers was fabricated. The micelle and vesicle phases were characterized in detail by cryogenic transmission electron microscopy, polarized optical microscopy, dynamic light scattering, and rheological measurements. It can be clearly demonstrated that the structure of alkyl chain can significantly influence the surface adsorption, solution self-assembly, and aqueous two-phase system of pseudogemini surfactants. Our work provided a convenient technique to achieve controlled self-assembly by introducing positional isomers of surfactants.
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BACKGROUND: Essential public health services (EPHS) is general welfare public health interventions led by the Chinese government and provided by the primary medical institutions to all residents. In Beilin District, Xi'an, EPHS producers can be divided into outsourced institutions and public institutions. OBJECTIVE: Can outsourcing EPHS reduce costs and improve efficiency and quality? There is still no definite answer to this question. This paper compares the performance of outsourced institutions and public institutions in terms of efficiency and quality, explains the reasons for this phenomenon. METHODS: This paper uses a theoretical and two-stage DEA model Based on a "triple subject" research framework. RESULTS: The results show that the difference between public institutions and outsourced institutions is mainly reflected in service quality. When the quality is not measured, outsourced institutions' production efficiency is higher than that of public institutions. When there are quality measurements, the production efficiency of outsourced institutions is lower than that of public institutions. CONCLUSIONS: Outsourced institutions perform worse than public institutions. The reason is that a bilateral monopolistic market structure has formed between local governments and outsourced institutions. This situation makes it difficult for the government to replace poor quality outsourced institutions under the constraints of a limited budget.
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Servicios de Salud , Servicios Externos , China , Gobierno LocalRESUMEN
The pathogenesis of depression is unclear, and it responds poorly to treatment. It is thus urgent to identify the pathogenesis of depression and possible therapeutic targets. There may be interactions between insulin resistance (IR) and depression. The purpose of this study was to explore the relationship between depression, triglyceride glucose (TyG) index. The study participants were 198 middle-aged and elderly patients who were admitted to the Hebei General Hospital between January 1, 2021, and August 31, 2022, together with 189 healthy adults as controls. Depression was diagnosed according to ICD-10 diagnostic criteria for depression. IR was assessed by the TyG index. Compared with the control group, patients suffering from depression had higher TyG index (Pâ =â .00); There were significant differences in the sex ratio (Pâ =â .00), family history (Pâ =â .00), body mass index (Pâ =â .008), total cholesterol (Pâ =â .00), fasting blood glucose (Pâ =â .004), high-density lipoprotein (Pâ =â .00), and low-density lipoprotein (Pâ =â .001) levels between the 2 groups. After excluding other confounding factors, the TyG index was found to be independently associated with depression, with an OR of 2.75. These data support an association of depression with the TyG index. IR thus appears to be a risk factor for depression.
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Glucosa , Resistencia a la Insulina , Anciano , Persona de Mediana Edad , Humanos , Adulto , Triglicéridos , Estudios Transversales , Glucemia , Depresión/epidemiología , BiomarcadoresRESUMEN
Current treatments for esophageal squamous cell carcinoma (ESCC) have limited efficacy. Therefore, the development of novel therapeutic targets to effectively manage the disease and boost survival rates is imperative Neferine, a natural product extracted from Nelumbo nucifera (lotus) leaves, has been revealed to inhibit the growth of hepatocarcinoma, breast cancer and lung cancer cells. However, its effect on ESCC is unknown. In the present study, it was revealed that neferine exerted antiproliferative effects in ESCC. It was also revealed that it triggered arrest of the G2/M phase and enhanced apoptosis of ESCC cell lines. Moreover, its ability to trigger accumulation of reactive oxygen species (ROS) and activate the cJun Nterminal kinase (JNK) pathway was demonstrated. Further study revealed how Nacetyl cysteine (NAC), a ROS inhibitor, attenuated these effects, demonstrating that ROS and JNK inhibitors mediated a marked reversal of neferinetriggered cell cycle arrest and apoptosis in ESCC cells. Finally, it was revealed that neferine was involved in the inhibition of Nrf2, an antioxidant factor. Collectively, these findings demonstrated the antitumor effect of neferine in ESCC, through the ROSmediated JNK pathway and inhibition of Nrf2, indicating its potential as a target for development of novel and effective therapeutic agents against ESCC.
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Antineoplásicos Fitogénicos/farmacología , Bencilisoquinolinas/farmacología , Neoplasias Esofágicas/tratamiento farmacológico , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Antineoplásicos Fitogénicos/uso terapéutico , Apoptosis/efectos de los fármacos , Bencilisoquinolinas/uso terapéutico , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/patología , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Factor 2 Relacionado con NF-E2/antagonistas & inhibidores , Factor 2 Relacionado con NF-E2/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Euryarchaeal lineages have been believed to have a methanogenic last common ancestor. However, members of euryarchaeal Archaeoglobi have long been considered nonmethanogenic and their evolutionary history remains elusive. Here, three high-quality metagenomic-assembled genomes (MAGs) retrieved from high-temperature oil reservoir and hot springs, together with three newly assembled Archaeoglobi MAGs from previously reported hot spring metagenomes, are demonstrated to represent a novel genus of Archaeoglobaceae, "Candidatus Methanomixophus." All "Ca Methanomixophus" MAGs encode an M methyltransferase (MTR) complex and a traditional type of methyl-coenzyme M reductase (MCR) complex, which is different from the divergent MCR complexes found in "Ca Polytropus marinifundus." In addition, "Ca Methanomixophus dualitatem" MAGs preserve the genomic capacity for dissimilatory sulfate reduction. Comparative phylogenetic analysis supports a laterally transferred origin for an MCR complex and vertical heritage of the MTR complex in this lineage. Metatranscriptomic analysis revealed concomitant in situ activity of hydrogen-dependent methylotrophic methanogenesis and heterotrophic fermentation within populations of "Ca Methanomixophus hydrogenotrophicum" in a high-temperature oil reservoir.IMPORTANCE Current understanding of the diversity, biology, and ecology of Archaea is very limited, especially considering how few of the known phyla have been cultured or genomically explored. The reconstruction of "Ca Methanomixophus" MAGs not only expands the known range of metabolic versatility of the members of Archaeoglobi but also suggests that the phylogenetic distribution of MCR and MTR complexes is even wider than previously anticipated.
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Methanogenic hydrocarbon degradation is an important biogeochemical process in oil reservoirs; however, genomic DNA-based analysis of microorganisms and metabolite detection are not conclusive for identification of the ongoing nature of this bioprocess. In this study, a suite of analyses, involving the study of microbial community and selective gene quantification of both genomic DNA and RNA together with signature metabolites, were performed to comprehensively advance the understanding of the methanogenic biodegradation of hydrocarbons in a low-temperature oilfield. The fumarate addition products for alkanes-C4, C5, and C7-alkylsuccinates-and transcribed assA and mcrA genes were simultaneously detected in the production water sample, providing robust and convincing evidence for both the initial activation of n-alkanes and methane metabolism in this oilfield. The clone library of assA gene transcripts showed that Smithella was active and most likely responsible for the addition of fumarate to n-alkanes, whereas Methanoculleus and Methanothrix were the dominant and active methane-producers via CO2 reduction and acetoclastic pathways, respectively. Additionally, qPCR results of assA and mcrA genes and their transcribed gene copy numbers revealed a roughly similar transcriptional activity in both n-alkanes-degraders and methane producers, implying that they were the major participants in the methanogenic degradation of n-alkanes in this oilfield. To the best of our knowledge, this is the first report presenting sufficient speculation, through detection of signature intermediates, corresponding gene quantification at transcriptional levels, and microbial community analysis, of methanogenic degradation of n-alkanes in production water of an oil reservoir.
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Alcanos , Deltaproteobacteria/genética , Biodegradación Ambiental , Metano , Yacimiento de Petróleo y Gas , Filogenia , ARN Ribosómico 16S , Temperatura , AguaRESUMEN
Paraffinic n-alkanes (C22-C30), crucial portions of residual oil, are generally considered to be difficult to be biodegraded owing to their general solidity at ambient temperatures and low water solubility, rendering relatively little known about metabolic processes in different methanogenic hydrocarbon-contaminated environments. Here, we established a methanogenic C22-C30 n-alkane-degrading enrichment culture derived from a high-temperature oil reservoir production water. During two-year incubation (736 days), unexpectedly significant methane production was observed. The measured maximum methane yield rate (164.40 µmol L-1 d-1) occurred during the incubation period from day 351 to 513. The nearly complete consumption (> 97%) of paraffinic n-alkanes and the detection of dicarboxylic acids in n-alkane-amended cultures indicated the biotransformation of paraffin to methane under anoxic condition. 16S rRNA gene analysis suggested that the dominant methanogen in n-alkane-degrading cultures shifted from Methanothermobacter on day 322 to Thermoplasmatales on day 736. Bacterial community analysis based on high-throughput sequencing revealed that members of Proteobacteria and Firmicutes exhibiting predominant in control cultures, while microorganisms affiliated with Actinobacteria turned into the most dominant phylum in n-alkane-dependent cultures. Additionally, the relative abundance of mcrA gene based on genomic DNA significantly increased over the incubation time, suggesting an important role of methanogens in these consortia. This work extends our understanding of methanogenic paraffinic n-alkanes conversion and has biotechnological implications for microbial enhanced recovery of residual hydrocarbons and effective bioremediation of hydrocarbon-containing biospheres.
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Most main oilfields in China have already entered a "double high" development stage (high water cut, high recovery degree). To further enhance oil recovery in reservoirs after polymer flooding (RAPFs), an efficient activator formulation for promoting metabolism of endogenous microorganism was studied by aerogenic experiments, physical simulation experiments, electron microscopy scanning and pyrophosphate sequencing. Results show that the activator could activate the endogenous microorganisms in the injected water and make the pressurized gas reach 2 MPa after 60 d static culture of the activator in a high pressure vessel. The oil recovery efficiency of natural core physical simulation flooding can be improved by more than 3.0% (OOIP) in RAPFs when injected 0.35 PV activator with 1.8% mass concentration, and a lot of growth and reproduction of activated endogenous microorganism in the core was observed by electron microscopy scanning. Field trial with 1 injector and 4 producers was carried out in the east of south II block of Sa Nan in December 2011. By monitoring four effective production wells, changes of carbon isotope δ13C (PDB) content of methane and carbon dioxide were -45 per thousand to -54 per thousand and 7 per thousand to 12 per thousand. Compared with east II of Sa Nan block, the oil amount increased by 35.9%, water cut stabled at 94%. The incremental oil was 5 957 t during the three and a half years, which provides an alternative approach for further improving oil recovery in similar reservoirs.
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Yacimiento de Petróleo y Gas/microbiología , Polímeros , Microbiología del Agua , Dióxido de Carbono/química , Isótopos de Carbono/análisis , China , Difosfatos/química , Metano/química , AguaRESUMEN
A bacterial isolate, designated as DQ8, was found capable of degrading diesel, crude oil, n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in petroleum. Strain DQ8 was assigned to the genus Pseudomonas aeruginosa based on biochemical and genetic data. The metabolites identified from n-docosane as substrate suggested that P. aeruginosa DQ8 could oxidize n-alkanes via a terminal oxidation pathway. P. aeruginosa DQ8 could also degrade PAHs of three or four aromatic rings. The metabolites identified from fluorene as substrate suggested that P. aeruginosa DQ8 may degrade fluorene via two pathways. One is monooxygenation at C-9 of fluorene, and the other is initiated by dioxygenation at C-3 and C-4 of fluorene. P. aeruginosa DQ8 should be of great practical significance both in bioremediation of oil-contaminated soils and biotreatment of oil wastewater.
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Alcanos/metabolismo , Fluorenos/metabolismo , Petróleo/análisis , Hidrocarburos Policíclicos Aromáticos/metabolismo , Pseudomonas aeruginosa/metabolismo , Alcanos/análisis , Biodegradación Ambiental , Cromatografía de Gases y Espectrometría de Masas , Oxidación-Reducción , Hidrocarburos Policíclicos Aromáticos/análisisRESUMEN
A collection of 38 bacteria was obtained by enrichment cultivation from oil-contaminated soils of an oil field in Daqing, China. Twenty-two strains could utilize diesel oil as the sole source of carbon and energy, and 11 strains could degrade the total petroleum hydrocarbons (TPHs) of diesel oil by more than 70% in 7d. Phylogenetically, 19 of the bacteria related to Bacillus species. About 87.5% TPHs of crude oil were degraded by a consortium of seven strains. Denaturing gradient gel electrophoresis analysis suggested that five of the strains persisted throughout the degradation process. The collection of isolated bacteria might be a useful resource for bioremediation of oil-contaminated soils and biotreatment of oil wastewater.