We present an improved fractal model for pore structure evaluation and permeability estimation based on the high pressure mercury porosimetry data. An accumulative fractal equation is introduced to ...characterize the piecewise nature of the capillary pressure and the mercury saturation. The iterative truncated singular value decomposition algorithm is developed to solve the accumulative fractal equation and obtain the fractal dimension distributions. Furthermore, the fractal dimension distributions and relevant parameters are used to characterize the pore structure and permeability. The results demonstrate that the proposed model provides better characterization of the mercury injection capillary pressure than conventional monofractal theory. In addition, there is a direct relationship between the pore structure types and the fractal dimension spectrums. What is more, the permeability is strongly correlated with the geometric and the arithmetic mean values of fractal dimensions, and the permeability estimated using these new fractal dimension parameters achieve excellent result. The improved model and solution give a fresh perspective of the conventional monofractal theory, which may be applied in many geological and geophysical fields.
Key Points
An accumulative equation is introduced considering the piecewise nature of many conventional fractal data
An iterative truncated singular value decomposition algorithm is developed to obtain the fractal dimension spectrums
Parameters extracted from the fractal dimension spectrums can interpret the petrophysical information properly
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•Microemulsion preferentially solubilized more polar CHs in mixture.•The selective solubilization was strengthened with increasing temperature.•Increasing flow rate, media size, ...saturation inhibited priority solubilization.•Lower injection velocity and tinier size media improved removal efficiency.
The chlorinated hydrocarbons (CHs) are typically released to the aquifer as complex mixture, and the contaminant type takes the critical action on the in-situ microemulsion formation and solubilization behaviors. However, few interst has been paid to the solubilization behaviors of microemulsion for multiply CHs and the factors affecting selective solubilization. The current work investigated the effect of hydrogeochemical conditions on microemulsion competitive solubilization, and focused on the selective desorption and removal performance of in-situ microemulsion drenching under the various drenching situations. The results elucidated that the apparent solubility of CH was enhanced with adding inorganic salts and the decreasing temperature. In-situ microemulsion showed a preference for dissolving the more polar CHs (CF) in chlorinated hydrocarbon mixture. The selective solubilization was strengthened with increasing temperature, independent of alcohols and salts. The removal efficiency of microemulsion drenching for multiply CHs could achieve 96.0 %, improving with the tinier particle media and lower flow rates. Compared to other CHs, CF was more likely to be desorbed from aquifer medium in multicomponent systems. Furthermore, the selective desorption for multiply CHs was associated with flow rates, media size and residual saturation of contaminants. The inhibition for preferential desorption was more intense to the increase of injection velocity, media size and residual saturation. This insight of selective solubilization behavior can be used to advances the application of in-situ microemulsion drenching for site remediation of multiply CHs.
Experimental works have proved that imbibition under forced pressure (FP, the difference between hydraulic fluid pressure and original pore pressure) has a positive effect on fossil hydrogen energy ...development in tight oil reservoir. However, the knowledge of the influence of imbibition under forced pressure (forced imbibition, FI) on fracturing fluid flowback and water retention is still limited. In this paper, experiments were designed and conducted to reveal the mechanism of fracturing fluid flowback and water retention under imbibition effect in tight sandstones. As a comparison, unconsolidated sandstones were also investigated in this study. Core samples were divided into two categories: the imbibition ones (treated by imbibition) and the filtration ones (treated by displacement), in accordance with the real oil-water distribution after well shut-in. An imbibition core and a filtration core were stitched together to conduct a flowback experiment. During the experiment, fluid distribution in different pore sizes was monitored continuously by using a low-field nuclear magnetic resonance device. Results show that the flowback recovery in tight sandstones is much lower than that in unconsolidated sandstones due to the difference of pore structure. Meanwhile, forced imbibition leads to higher oil recovery than spontaneous imbibition (SI) in tight sandstones since forced pressure enhances water imbibition. The water imbibed into small-macro and macro pores contributes the major flowback recovery, but the imbibed water in micro pores is rather difficult to displace and finally retains in these pores during the flowback process. Overall, forced imbibition not only enhances oil recovery but also increases water retention, explaining the mechanism of well productivity increase by using the shut-in method in the field. This study can help to clarify the influence of forced imbibition on fracturing fluid flowback and enhancement of fossil hydrogen development, and further provide guidance for flowback designs.
•The flowback process in tight sandstone was experimentally investigated.•The influence of forced pressure on imbibition was studied.•The effect of imbibition on water retention was revealed.
To fundamentally study the effect of wettability on sandstone conductivity, a series of experiments, including rock-electricity, nuclear magnetic resonance (NMR) and wettability tests, were conducted ...systematically on high- and low-permeability sandstone samples. The results show that wettability had different influence on the conductivity laws of high- and low-permeability sandstones, which was mainly caused by the complex combination of pore and pore-throat. The conductivity laws of oil-wet high-permeability sandstones, which mainly developed large pores and coarse throats with small water-wet bound space, were mainly followed the oil-wet conduction law. However, the preferentially oil-wet low-permeability sandstones primarily developed middle-to-small pores and micro throats with large water-wet bound space. Hence, the large amount of bound space followed the water-wet conduction law, while the relatively large pore with oil-wet property was dominated by oil-wet conduction law. Consequently, the conductivity of oil-wet sandstones with low-permeability was co-controlled by the wettability and pore structure. The study can result in a quite different saturation under the same resistivity compared with the Archie’s law, and provide a meaningful guidance for establishing oil-saturation calculation model, which can improve the oil-layer identification accuracy and eventually enhance the oil-wet reservoir recovery.
Bone osteogenic sarcoma has a poor prognosis as the exact cell of origin and the signaling pathways underling tumor formation remain undefined. Here, we report an osteogenic tumor mouse model based ...on the conditional knockout of liver kinase b1 (Lkb1; also known as Stk11) in Cathepsin K (Ctsk)-Cre expressing cells. Lineage tracing studies demonstrated that Ctsk-Cre could label a population of periosteal cells. The cells functioned as mesenchymal progenitors with regard to markers and functional properties. LKB1 deficiency increased proliferation and osteoblast differentiation of Ctsk+ periosteal cells, while downregulation of mTORC1 activity, using Raptor genetic mouse model or mTORC1 inhibitor treatment, ameliorated tumor progression of Ctsk-Cre Lkb1fllfl mice. Xenograft mouse models, using human osteosarcoma cell lines, also demonstrated that LKB1 deficiency promoted tumor formation, while mTOR inhibition suppressed xenograft tumor growth. In summary, we identified periosteum-derived Ctsk-Cre expressing cells as a cell of origin for osteogenic tumor and suggested the LKB1-mTORC1 pathway as a promising target for treatment of osteogenic tumor.
Tissues derive ATP from two pathways-glycolysis and the tricarboxylic acid (TCA) cycle coupled to the electron transport chain. Most energy in mammals is produced via TCA metabolism
. In tumours, ...however, the absolute rates of these pathways remain unclear. Here we optimize tracer infusion approaches to measure the rates of glycolysis and the TCA cycle in healthy mouse tissues, Kras-mutant solid tumours, metastases and leukaemia. Then, given the rates of these two pathways, we calculate total ATP synthesis rates. We find that TCA cycle flux is suppressed in all five primary solid tumour models examined and is increased in lung metastases of breast cancer relative to primary orthotopic tumours. As expected, glycolysis flux is increased in tumours compared with healthy tissues (the Warburg effect
), but this increase is insufficient to compensate for low TCA flux in terms of ATP production. Thus, instead of being hypermetabolic, as commonly assumed, solid tumours generally produce ATP at a slower than normal rate. In mouse pancreatic cancer, this is accommodated by the downregulation of protein synthesis, one of this tissue's major energy costs. We propose that, as solid tumours develop, cancer cells shed energetically expensive tissue-specific functions, enabling uncontrolled growth despite a limited ability to produce ATP.
Comparisons of measured and fluid corrected magnetizations and T2 spectrums.
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•Permeability of bioclastic limestone is governed by open and connected pores.•Pore radius is positively ...correlated with T2, and varies in different ranges.•Downhole NMR should be corrected to eliminate influences of fluid components.
Permeability is an important parameter in formation evaluation since it controls the fluid transportation of porous rocks. However, it is challengeable to compute the permeability of bioclastic limestone reservoirs by conventional methods linking petrophysical and geophysical data, due to the complex pore distributions. A new method is presented to estimate the permeability based on laboratory and downhole nuclear magnetic resonance (NMR) measurements. We divide the pore space into four intervals by the inflection points between the pore radius and the transversal relaxation time. Relationships between permeability and percentages of different pore intervals are investigated to investigate influential factors on the fluid transportation. Furthermore, an empirical model, which takes into account of the pore size distributions, is presented to compute the permeability. 212 core samples in our case show that the accuracy of permeability calculation is improved from 0.542 (SDR model), 0.507 (TIM model), 0.455 (conventional porosity-permeability regressions) to 0.803. To enhance the precision of downhole application of the new model, we developed a fluid correction algorithm to construct the water spectrum of in-situ NMR data, aiming to eliminate the influence of oil on the magnetization. The result reveals that permeability is positively correlated with percentages of mega-pores and macro-pores, but negatively correlated with the percentage of micro-pores. Poor correlation is observed between permeability and the percentage of meso-pores. NMR magnetizations and T2 spectrums after the fluid correction agree well with laboratory results for samples saturated with water. Field application indicates that the improved method provides better performance than conventional models such as Schlumberger-Doll Research equation, Timur-Coates equation, and porosity-permeability regressions.
The remediation of trichloroethylene contaminated groundwater by permanganate-based in situ chemical oxidation is limited by MnO2 formation. The application of phase transfer catalyst (PTC) is a ...promising alternative to enhance remediation efficiency, and the alleviation of MnO2 generation is one of crucial capacities of PTC to promote oxidation. This work has emphatically elucidated the mechanism of MnO2 alleviation by PTC, as well as the effectiveness which was researched by conducting batch and sand column experiments. The results indicated that the contents of MnO2 suspended in aqueous phase and total manganese in the media were respectively decreased by 29.5% and 26.1% attributed to PTC addition. Although PTC could not be used as a chelator for Mn(Ⅲ) stabilization, the generation of dissolved Mn(Ⅱ) and Mn(Ⅲ) was promoted by PTC for less MnO2 generation. Further studies illustrated that redox reactions would occur between dissolved Mn(Ⅱ)/Mn(Ⅲ) and TCE, which benefited TCE degradation. Moreover, Smaller particle size and improved colloidal stabilization of formed MnO2 were achieved by PTC to minimize MnO2 precipitation. Overall, effective alleviation of the MnO2 generation and precipitation by PTC is collectively contributed from the promotion of dissolved Mn(Ⅱ) and Mn(Ⅲ) and the stabilization of MnO2 formed in situ.
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As an essential trace element, appropriate boron supplementation can promote immune function of animals. To illustrate the effects of boron in a rat model, RNA-Seq was conducted for the RNA from ...duodenum after treatment with different concentration of boron in which boron was given in the form of boric acid. More than 47 million reads were obtained in 0, 10, and 320 mg/L boron (0, 57.21, and 1830.66 mg/L boric acid) treatment groups that produced 58 965 402, 48 607 328, and 46 760 660 clean reads, respectively. More than 95% of the clean reads were successfully matched to the rat reference genome and assembled to generate 32 662 transcripts. A total of 624 and 391 differentially expressed candidate genes (DEGs) were found between 0 vs.10 and 0 vs. 320 mg/L boron comparison groups. We also identified transcription start site, transcription terminal site, and skipped exons as the main alternative splicing events. GO annotations revealed most of DEGs were involved in the regulation of immune activity. The DEGs were enriched in influenza A, herpes simplex infection, cytosolic DNA-sensing pathway, and antigen processing and presentation signaling pathways. The expression levels of genes enriched in these signaling pathways indicate that lower doses of boron could achieve better effects on promoting immune response in the duodenum. These effects on the immune system appear to be mediated via altering the expression patterns of genes involved in the related signaling pathways in a dose-dependent pattern. These data provide more insights into the molecular mechanisms of immune regulation in rats in response to dietary boron treatment.
Resveratrol, a type of natural polyphenol mainly extracted from the skin of grapes, has been reported to protect against inflammatory responses and exert anxiolytic effect. Yes-associated protein ...(YAP), a major downstream effector of the Hippo signaling pathway, plays a critical role in inflammation. The present study aimed to explore whether YAP pathway was involved in the anxiolytic effect of resveratrol in lipopolysaccharide (LPS)-treated C57BL/6J male mice. LPS treatment induced anxiety-like behavior and decreased sirtuin 1 while increased YAP expression in the hippocampus. Resveratrol attenuated LPS-induced anxiety-like behavior, which was blocked by EX-527 (a sirtuin 1 inhibitor). Mechanistically, the anxiolytic effects of resveratrol were accompanied by a marked decrease in YAP, interleukin-1β and ionized calcium binding adaptor molecule 1 (Iba-1) while a significant increase in autophagic protein expression in the hippocampus. Pharmacological study using XMU-MP-1, a YAP activator, showed that activating YAP could induce anxiety-like behavior and neuro-inflammation as well as decrease hippocampal autophagy. Moreover, activation of YAP by XMU-MP-1 treatment attenuated the ameliorative effects of resveratrol on LPS-induced anxiety-like behavior, while blockade of YAP activation with verteporfin, a YAP inhibitor, attenuated LPS-induced anxiety-like behavior and neuro-inflammation as well as hippocampal autophagy. Finally, rapamycin-mediated promotion of autophagy attenuated LPS-induced anxiety-like behavior and decreased interleukin-1β and Iba-1 expression in the hippocampus. Collectively, these results indicate that amelioration by resveratrol in LPS-induced anxiety-like behavior is through attenuating YAP-mediated neuro-inflammation and promoting hippocampal autophagy, and suggest that inhibition of YAP pathway could be a potential therapeutic target for anxiety-like behavior induced by neuro-inflammation.
•Resveratrol ameliorates LPS-induced anxiety-like behavior by attenuating YAP signaling.•YAP-mediated neuro-inflammation contributes to LPS-induced anxiety-like behavior.•Rapamycin prevents neuro-inflammation and attenuates LPS-induced anxiety-like behavior.•Blocking YAP could be a therapeutic target for LPS-induced anxiety-like behavior.
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