179 research outputs found

    Study on flow unit division and production dynamics of tight sandstone reservoir in Huaqing oilfield

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    758-764In this paper, the Chang 6 ultra-low permeability reservoirs in Huaqjing area of Ordos Basin are studied. The reservoir is divided into four types of flow units by using Q-type multi-parameter clustering analysis and SPSS statistical analysis software. The characteristics of reservoir physical properties, sedimentary characteristics, capillary pressure curve and production dynamics were analyzed. The rationality of the results were verified from the static and dynamic points of view. Results show that I type flow unit has good reservoir properties and development effect is fast. The main development target is to maintain long-term stability. The distribution areas of II and III types are large, and cover the main production layer of oil field development and the remaining oil enrichment area. The reservoir properties of the IV type flow unit are worst, and the development is difficult. Efficient development of such reservoirs through the scientific division of the flow unit is important and of practical significance

    Advanced characterization of coal microstructure before and after liquid nitrogen cold soaking

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    With the development of coal seam fracturing technology, promote the gas extraction by liquid nitrogen cold soaking fracturing coal has attracted widespread attention. In order to study the effect of liquid nitrogen cold soaking on the microstructures of different coals (lean coal, fat coal and anthracite) before and after liquid nitrogen cold soaking, the scanning electron microscopy (SEM), pore size distribution instrument and physical adsorption instrument were jointly characterized. The influence of liquid nitrogen cold soaking on the distribution of pore volume and specific surface area of different coal samples was comparatively analyzed. The results show that the thermal stress generated during the liquid nitrogen cold soaking destroys the microstructure of the coal or causes the initiation of micro-cracks, After liquid nitrogen cold soaking, the total pore volume and specific surface area of coal samples increase. The total pore volume growth rate of fat coal is the lowest, followed by anthracite, and the lean coal’s is the highest. The volume of micropores, micropores, meso-pores and macropores/fractures in the coal samples increase. cold leaching of liquid nitrogen causes macropores to pass through and form macropores/fissures in coal samples, resulting in the reduction of pore volume of macropores. After liquid nitrogen cold soaking, the pore specific surface area of each coal sample concentrate in the range of 10 − 100 nm, and has obvious peak characteristics. Liquid nitrogen cold soaking can increase the adsorption capacity of lean coal, fat coal and anthracite coal samples, and the adsorption capacity difference is the largest in the middle high pressure region (0.4 < p/p0 < 1.0). Liquid nitrogen cold soaking can effectively transform the internal microstructure of different coals. The research results are helpful to reveal the spatial expansion and connectivity of macroscopic and microscopic pore fractures in coal reservoirs during liquid nitrogen cracking

    Hypertensive nephropathy treatment by heart-protecting musk pill: a study of anti-inflammatory therapy for target organ damage of hypertension

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    This study was designed to investigate the protective effect of the heart-protecting musk pill (HMP) on inflammatory injury of kidney from spontaneously hypertensive rat (SHR). Male SHRs aged 4 weeks were divided into SHR model group, HMP low-dosage group (13.5 mg/kg), and HMP high-dosage group (40 mg/kg). Age-matched Wistar–Kyoto rats were used as normal control. All rats were killed at 12 weeks of age. Tail-cuff method and enzyme-linked immunosorbent assay were used to determine rat systolic blood pressure and angiotensin II (Ang II) contents, respectively. Renal inflammatory damage was evaluated by the following parameters: protein expressions of inflammatory cytokines, carbonyl protein contents, nitrite concentration, infiltration of monocytes/macrophages in interstitium and glomeruli, kidney pathological changes, and excretion rate of urinary protein. HMP did not prevent the development of hypertension in SHR. However, this Chinese medicinal compound decreased renal Ang II content. Consistent with the change of renal Ang II, all the parameters of renal inflammatory injury were significantly decreased by HMP. This study indicates that HMP is a potent suppressor of renal inflammatory damage in SHR, which may serve as a basis for the advanced preventive and therapeutic investigation of HMP in hypertensive nephropathy

    Numerical approach to a low pressure gas-injection scroll compressor

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    In order to solve problems arising in ordinary heat pump system for pure electric vehicles at ultra-low temperature, a low pressure gas-injection scroll compressor is designed, and a mathematical model is established. Comparison with the experimental results shows good accuracy of the theoretical prediction. Document type: Articl

    Serum Containing Tao-Hong-Si-Wu Decoction Induces Human Endothelial Cell VEGF Production via PI3K/Akt-eNOS Signaling

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    Tao-Hong-Si-Wu decoction (TSD) is a famous traditional Chinese medicine (TCM) and widely used for ischemic disease in China. TSD medicated serum was prepared after oral administration of TSD (1.6 g/kg) twice a day for 3 days in rats. TSD medicated serum induced human umbilical vein endothelial cells (HUVECs) proliferation, VEGF secretion, and nitric oxide (NO) production. These promoted effects of TSD were partly inhibited by treatment with PI3K inhibitor (LY294002) or eNOS inhibitor (L-NAME), respectively, and completely inhibited by treatment with LY294002 and L-NAME simultaneously. Western blot analysis findings further indicated that TSD medicated serum upregulated p-Akt and p-eNOS expressions, which were significantly inhibited by LY294002 or L-NAME and completely inhibited by both LY294002 and L-NAME; these results indicated that TSD medicated serum induced HUVECs VEGF expression via PI3K/Akt-eNOS signaling. TSD medicated serum contains hydroxysafflor yellow A, ferulic acid, and ligustilide detected by UPLC with standards, so these effect of TSD medicated serum may be associated with these three active compounds absorbed in serum

    Dietary sodium enhances the expression of SLC4 family transporters, IRBIT, L-IRBIT, and PP1 in rat kidney: Insights into the molecular mechanism for renal sodium handling

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    The kidney plays a central role in maintaining the fluid and electrolyte homeostasis in the body. Bicarbonate transporters NBCn1, NBCn2, and AE2 are expressed at the basolateral membrane of the medullary thick ascending limb (mTAL). In a previous study, NBCn1, NBCn2, and AE2 are proposed to play as a regulatory pathway to decrease NaCl reabsorption in the mTAL under high salt condition. When heterologously expressed, the activity of these transporters could be stimulated by the InsP3R binding protein released with inositol 1,4,5-trisphosphate (IRBIT), L-IRBIT (collectively the IRBITs), or protein phosphatase PP1. In the present study, we characterized by immunofluorescence the expression and localization of the IRBITs, and PP1 in rat kidney. Our data showed that the IRBITs were predominantly expressed from the mTAL through the distal renal tubules. PP1 was predominantly expressed in the TAL, but is also present in high abundance from the distal convoluted tubule through the medullary collecting duct. Western blotting analyses showed that the abundances of NBCn1, NBCn2, and AE2 as well as the IRBITs and PP1 were greatly upregulated in rat kidney by dietary sodium. Co-immunoprecipitation study provided the evidence for protein interaction between NBCn1 and L-IRBIT in rat kidney. Taken together, our data suggest that the IRBITs and PP1 play an important role in sodium handling in the kidney. We propose that the IRBITs and PP1 stimulates NBCn1, NBCn2, and AE2 in the basolateral mTAL to inhibit sodium reabsorption under high sodium condition. Our study provides important insights into understanding the molecular mechanism for the regulation of sodium homeostasis in the body

    Characterisation of the mucilage polysaccharides from Dioscorea opposita Thunb. with enzymatic hydrolysis

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    The mucilage polysaccharides from Dioscorea opposita (DOMP) were extracted and treated with a single/dual enzymatic hydrolysis. The characterisation and viscosity were subsequently investigated in this study. DOMP obtained 62.52% mannose and 23.45% glucose. After single protease and trichloroacetic acid (TCA) treatments, the mannose content was significantly reduced to 3.96%, and glucose increased from 23.45% to 45.10%. Dual enzymatic hydrolysis also decreased the mannose and glucose contents to approximately 18%-35% and 7%-19%, respectively. The results suggest that enzymatic degradation could effectively remove the protein from DOMP accompanied by certain polysaccharides, especially mannose. The molecular weight, surface morphology, viscosity and particle sizes were measured. Enzymatic hydrolysis reduced molecular weight, decreased the viscosity, and increased the particle sizes, which indicates that the characterisations of DOMP samples were altered as structures changed. This study was a basic investigation into characterisation of DOMP to contribute to the processing of food by-products.Peer reviewe

    Metabolomics and transcriptomics analyses for characterizing the alkaloid metabolism of Chinese jujube and sour jujube fruits

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    IntroductionJujube is an important economic forest tree whose fruit is rich in alkaloids. Chinese jujube (Ziziphus jujuba Mill.) and sour jujube (Ziziphus spinosa Hu.) are the two most important species of the jujube genus. However, the mechanisms underlying the synthesis and metabolism of alkaloids in jujube fruits remain poorly understood.MethodsIn this study, the fruits of Ziziphus jujuba ‘Hupingzao’ and Ziziphus spinosa ‘Taigusuanzao’ in different harvest stages were used as test materials, we first integrated widely targeted metabolomics and transcriptomics analyses to elucidate the metabolism of alkaloids of jujube fruits.ResultsIn the metabolomics analysis, 44 alkaloid metabolites were identified in 4 samples, 3 of which were unique to sour jujube fruit. The differential alkaloid metabolites (DAMs) were more accumulated in sour jujube than in Chinese jujube; further, they were more accumulated in the white ripening stage than in the red stage. DAMs were annotated to 12 metabolic pathways. Additionally, transcriptomics data revealed 259 differentially expressed genes (DEGs) involved in alkaloid synthesis and metabolism. By mapping the regulatory networks of DAMs and DEGs, we screened out important metabolites and 11 candidate genes.DiscussionThis study preliminarily elucidated the molecular mechanism of jujube alkaloid synthesis. The candidate genes regulated the synthesis of key alkaloid metabolites, but the specific regulation mechanism is unclear. Taken together, our results provide insights into the metabolic networks of alkaloid synthesis in Chinese jujube and sour jujube fruits at different harvest stages, thereby providing a theoretical reference for further research on the regulatory mechanism of jujube alkaloids and their development and utilization
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