Modeling pressure calculations in a stress-sensitive reservoir with a multistage fractured horizontal well

Peng Chen,Kangliang Guo,Ning Li,Song Lu,Lili Lin 한국자원공학회 2019 Geosystem engineering Vol.22 No.6

Fractured horizontal wells have been widely used in tight reservoirs. The distribution of the formation pressure is related to the fracturing design, well pattern optimization and development effect. In addition, there is generally a stress sensitivity effect in tight reservoirs, which makes the pressure distribution more complex. Therefore, it is necessary to analyze the formation pressure distribution in the development process of tight reservoirs by fractured horizontal wells. In this paper, using the Pedrosa transform, perturbation transform, Green formula and boundary element method, a pressure calculation model is first built and solved for a stress-sensitive reservoir with a multistage fractured horizontal well. Second, comparing the bottom hole pressure of this method with those of existing tight reservoir models illustrates the accuracy of this model. Finally, pressure contours with different permeability moduli and boundaries are obtained by solving the seepage model. The results indicate that this model can conveniently calculate the pressure at any position in stress-sensitive reservoirs with arbitrary boundaries. The pressure contours show that the stress-sensitive effect occurs mainly near the wellbore and affects the pressure distribution of this region. The results have a certain significance for fracturing design and well pattern optimization, which is beneficial for improving the development efficiency of tight oil reservoirs.

Antitumor and Immunomodulating Activity of Polysaccharides from Enteromorpha intestinalis

Lili Jiao,Liping Zhang,Peng Jiang,Mingjiang Wu 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.3

Two polysaccharides (WEA and WEB) were isolated from Enteromorpha intestinalis by hot water extraction, anion-exchange, and gel-permeation chromatography. The average molecular weights (Mw) of the two fractions were 72.03 kDa (WEA) and 60.12 kDa (WEB). WEA was composed of Rha, Xyl, Man, and Glc in a molar ratio of 1.39:1.00:0.13:3.23. WEB consisted of Rha, Xyl,Gal, and GlcA (glucuronic acid) in a molar ratio of 7.32:1.00:0.51:1.28. Both polysaccharides could inhibit tumor growth in S180 tumor-bearing mice, and increased the relative spleen and thymus weight. They also increased the expression of tumor necrosis factor-alpha (TNF-α) in serum. WEA and WEB induced lymphocyte proliferation,increased the production of TNF-α in macrophages, and stimulated macrophages to produce nitric oxide dosedependently through the up-regulation of inducible NO synthase activity. However, no direct cytotoxicity against Sarcoma 180 was investigated in vitro. These results indicate that the antitumor effects of these polysaccharides are associated with immunostimulation.

Wind characteristics of a strong typhoon in marine surface boundary layer

Lili Song,Q. S. Li,Wenchao Chen,Peng Qin,Haohui Huang,Y.C. He 한국풍공학회 2012 Wind and Structures, An International Journal (WAS Vol.15 No.1

High-resolution wind data were acquired from a 100-m high offshore tower during the passage of Typhoon Hagupit in September, 2008. The meteorological tower was equipped with an ultrasonic anemometer and a number of cup anemometers at heights between 10 and 100 m. Wind characteristics of the strong typhoon, such as mean wind speed and wind direction, turbulence intensity, turbulence integral length scale, gust factor and power spectra of wind velocity, vertical profiles of mean wind speed were investigated in detail based on the wind data recorded during the strong typhoon. The measured results revealed that the wind characteristics in different stages during the typhoon varied remarkably. Through comparison with non-typhoon wind measurements, the phenomena of enhanced levels of turbulence intensity, gust factors, turbulence integral length scale and spectral magnitudes in typhoon boundary layer were observed. The monitored data and analysis results are expected to be useful for the wind-resistant design of offshore structures and buildings on seashores in typhoon-prone regions.

Novel integrative soft computing for daily pan evaporation modeling

LiLi Liu,Yongjun Zhu,Yu Zhang,Peng Wang,Loke Kok Foong 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.30 No.4

Regarding the high significance of correct pan evaporation modeling, this study introduces two novel neurometaheuristic approaches to improve the accuracy of prediction for this parameter. Vortex search algorithms (VSA), sunflower optimization (SFO), and stochastic fractal search (SFS) are integrated with a multilayer perceptron neural network to create the VSA-MLPNN, SFO-MLPNN, and SFS-MLPNN hybrids. The climate data of Arcata-Eureka station (operated by the US environmental protection agency) belonging to the years 1986-1989 and the year 1990 are used for training and testing the models, respectively. Trying different configurations revealed that the best performance of the VSA, SFO, and SFS is obtained for the population size of 400, 300, and 100, respectively. The results were compared with a conventionally trained MLPNN to examine the effect of the metaheuristic algorithms. Overall, all four models presented a very reliable simulation. However, the SFS-MLPNN (mean absolute error, MAE = 0.0997 and Pearson correlation coefficient, R_P = 0.9957) was the most accurate model, followed by the VSA-MLPNN (MAE = 0.1058 and R_P = 0.9945), conventional MLPNN (MAE = 0.1062 and R_P = 0.9944), and SFO-MLPNN (MAE = 0.1305 and RP = 0.9914). The findings indicated that employing the VSA and SFS results in improving the accuracy of the neural network in the prediction of pan evaporation. Hence, the suggested models are recommended for future practical applications.

Preparation of modified graphene oxide/polyethyleneimine film with enhanced hydrogen barrier properties by reactive layer-by-layer self-assembly

Li, Peng,Chen, Kuo,Zhao, Lili,Zhang, Hongyu,Sun, Haixiang,Yang, Xiujie,Kim, Nam Hoon,Lee, Joong Hee,Niu, Q. Jason Elsevier Science Ltd 2019 Composites Part B, Engineering Vol.166 No.-

<P><B>Abstract</B></P> <P>Hydrogen barrier properties are characteristic of polymeric materials prepared with graphene; thus, they can be considered as a good substitute for the metal body of the traditional hydrogen storage tank. Graphene oxide/polymer layer-by-layer self-assembling film based on noncovalent force shows good hydrogen gas barrier properties. However, the dense film structure can be broken when the film is placed in water environment, especially acidic or alkaline environment, which induces to the leak of the hydrogen gas. Herein, a modified graphene oxide/polyethyleneimine reactive layer-by-layer self-assembled film for the hydrogen barrier was fabricated by the covalent bond self-assembled technology. Graphene oxide was modified with ethylene glycol diglycidyl ether to introduce epoxy groups that can react with polyethyleneimine to form covalent bonds. The modification time, modification pH value, and the feed ratio of graphene oxide/ethylene glycol diglycidyl ether were investigated in detail. Results indicate that the self-assembled films were prepared by covalent bonds between polyethyleneimine and modified graphene oxide. When the modification time was 6 h, pH value was 2, and the feed ratio of graphene oxide/ethylene glycol diglycidyl ether was 0.05/0.23, the hydrogen transmission rate of 10-bilayer modified graphene oxide/polyethyleneimine self-assembled films was 289 cm<SUP>3</SUP>/m<SUP>2</SUP>·24 h·0.1 MPa, which was decreased by 78.8% compared to that of the polyethylene terephthalate substrate films (1365 cm<SUP>3</SUP>/m<SUP>2</SUP>·24 h·0.1 MPa). Furthermore, the modified graphene oxide/polyethyleneimine reactive layer-by-layer self-assembled films exhibit acid-resistance, alkali-resistance, salt-resistance and thermal-resistance properties.</P>

Different distribution patterns of microorganisms between aquaculture pond sediment and water

Dai Lili,Liu Chengqing,Peng Liang,Song Chaofeng,Li Xiaoli,Tao Ling,Li Gu 한국미생물학회 2021 The journal of microbiology Vol.59 No.4

Aquatic microorganisms in the sediment and water column are closely related; however, their distribution patterns between these two habitats still remain largely unknown. In this study, we compared sediment and water microeukaryotic and bacterial microorganisms in aquaculture ponds from different areas in China, and analyzed the influencing environmental factors as well as the inter-taxa relationships. We found that bacteria were significantly more abundant than fungi in both sediment and water, and the bacterial richness and diversity in sediment were higher than in water in all the sampling areas, but no significant differences were found between the two habitats for microeukaryotes. Bacterial taxa could be clearly separated through cluster analysis between the sediment and water, while eukaryotic taxa at all classification levels could not. Spirochaetea, Deltaproteobacteria, Nitrospirae, Ignavibacteriae, Firmicutes, Chloroflexi, and Lentimicrobiaceae were more abundantly distributed in sediment, while Betaproteobacteria, Alphaproteobacter, Cyanobacteria, Roseiflexaceae, Dinghuibacter, Cryomorphaceae, and Actinobacteria were more abundant in water samples. For eukaryotes, only Cryptomonadales were found to be distributed differently between the two habitats. Microorganisms in sediment were mainly correlated with enzymes related to organic matter decomposition, while water temperature, pH, dissolved oxygen, and nutrient levels all showed significant correlation with the microbial communities in pond water. Intensive interspecific relationships were also found among eukaryotes and bacteria. Together, our results indicated that eukaryotic microorganisms are distributed less differently between sediment and water in aquaculture ponds compared to bacteria. This study provides valuable data for evaluating microbial distributions in aquatic environments, which may also be of practical use in aquaculture pond management.

Wind characteristics of a strong typhoon in marine surface boundary layer

Song, Lili,Li, Q.S.,Chen, Wenchao,Qin, Peng,Huang, Haohui,He, Y.C. Techno-Press 2012 Wind and Structures, An International Journal (WAS Vol.15 No.1

High-resolution wind data were acquired from a 100-m high offshore tower during the passage of Typhoon Hagupit in September, 2008. The meteorological tower was equipped with an ultrasonic anemometer and a number of cup anemometers at heights between 10 and 100 m. Wind characteristics of the strong typhoon, such as mean wind speed and wind direction, turbulence intensity, turbulence integral length scale, gust factor and power spectra of wind velocity, vertical profiles of mean wind speed were investigated in detail based on the wind data recorded during the strong typhoon. The measured results revealed that the wind characteristics in different stages during the typhoon varied remarkably. Through comparison with non-typhoon wind measurements, the phenomena of enhanced levels of turbulence intensity, gust factors, turbulence integral length scale and spectral magnitudes in typhoon boundary layer were observed. The monitored data and analysis results are expected to be useful for the wind-resistant design of offshore structures and buildings on seashores in typhoon-prone regions.

Luminescence properties and energy transfer behavior of single-component NaY(WO₄)₂:Tm³⁺/Dy³⁺/Eu³⁺ phosphors for ultraviolet-excited white light-emitting diodes

Du, Peng,Wang, Lili,Yu, Jae Su Elsevier 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.673 No.-

<P><B>Abstract</B></P> <P>The single-component NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:Tm<SUP>3+</SUP>/Dy<SUP>3+</SUP>/Eu<SUP>3+</SUP> color-controllable phosphors were synthesized by a facile high-temperature solid-state reaction technique. The X-ray diffraction patterns, field-emission electron scanning microscope images and photoluminescence (PL) spectra were measured to characterize the prepared phosphors. All the samples possessed pure tetragonal phase and consisted of micro-sized particles. Under ultraviolet light excitation, the characteristic emissions of Tm<SUP>3+</SUP>, Dy<SUP>3+</SUP> and Eu<SUP>3+</SUP> ions were observed. Moreover, the emission color of the NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:0.01Tm<SUP>3+</SUP>/<I>x</I>Dy<SUP>3+</SUP> phosphors was tuned from blue to white by adjusting the Dy<SUP>3+</SUP> ion concentration. The PL spectra revealed that there existed an efficient energy transfer (ET) from Tm<SUP>3+</SUP> to Dy<SUP>3+</SUP> ions and the ET mechanism was determined to be a resonant type <I>via</I> dipole–dipole interaction. Through theoretical calculation, the ET efficiency was found to be as high as 46.1% when <I>x</I> = 0.05 and the critical distance was 6.54 Å. With the introduction of Eu<SUP>3+</SUP> ions, the corrected color temperature of the products was modified and the emission color was also changed from pure white to reddish white. These obtained single-component white light-emitting NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:Tm<SUP>3+</SUP>/Dy<SUP>3+</SUP>/Eu<SUP>3+</SUP> phosphors were expected to be a potential candidate for phosphor-converted white light-emitting diode applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Under 358 nm excitation, the obtained samples exhibited the emissions of Tm<SUP>3+</SUP>, Dy<SUP>3+</SUP> and Eu<SUP>3+</SUP> ions. </LI> <LI> Owing to the ET from Tm<SUP>3+</SUP> to Dy<SUP>3+</SUP> ions, the emission color of the phosphors was changed from blue to white. </LI> <LI> The ET efficiency in the NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:0.01Tm<SUP>3+</SUP>/xDy<SUP>3+</SUP> phosphors was up to 46.1% when x = 0.05. </LI> <LI> Through theoretical analysis, the ET mechanism from Tm<SUP>3+</SUP> to Dy<SUP>3+</SUP> ions was the dipole–dipole interaction. </LI> <LI> With the tridoping of Eu<SUP>3+</SUP> ions, the CCT value of the as-prepared phosphors was modified. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Crocin alleviates neurotoxicity induced by bupivacaine in SH-SY5Y cells with inhibition of PI3K/AKT signaling

Lin Lili,Chen Zhen,Li Jun,Peng Jianye,Wang Jian,Feng Mingjun,Liu Tiancheng,Zhang Mengli,Wu Xian,Ai Fen,Shen Caijie 한국유전학회 2024 Genes & Genomics Vol.46 No.1

Background Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. Objective The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. Method Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. Result Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3β. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. Conclusion These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity. Background Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. Objective The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. Method Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. Result Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3β. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. Conclusion These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity.

Clinical Study on Safety and Efficacy of Microwave Ablation for Primary Hyperparathyroidism

Ying Wei,Lili Peng,Yan Li,Zhen-long Zhao,Ming-an Yu 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.5

Objective: To evaluate the safety, feasibility, and efficacy of microwave ablation (MWA) for the treatment of primary hyperparathyroidism (PHPT). Materials and Methods: This study enrolled 67 PHPT patients (22 men, 45 women; mean age, 56.0 ± 16.3 years; range, 18– 83 years) from January 2015 to December 2018. The laboratory data, including the serum intact parathyroid hormone (iPTH), calcium, phosphorus, and alkaline phosphatase (ALP) levels, were evaluated before MWA and again 2 hours, 1 day, 7 days, 1 month, 3 months, 6 months, 12 months, 18 months, and 24 months after. Results: Complete ablation was achieved with all 72 hyperplastic parathyroid glands found on the 67 patients enrolled, 64 of whom were treated in one session and 3 were treated over two sessions. The technical success rate was 100%. The median follow-up time was 13.6 months (range, 10.0–31.1 months). The clinical success rate was 89.4%. The volume reduction rate was 79.4% at 6 months. Compared to pre-MWA, the serum iPTH, calcium, phosphorus, and ALP levels had significantly improved 6 months post-MWA (iPTH, 157.3 pg/mL vs. 39.2 pg/mL; calcium, 2.75 ± 0.25 mmol/L vs. 2.34 ± 0.15 mmol/L; phosphorus, 0.86 ± 0.20 mmol/L vs. 1.12 ± 0.22 mmol/L; ALP, 79 U/L vs. 54 U/L, respectively; all, p < 0.01). Hoarseness was a major complication in 4 patients (6.0%), but it improved spontaneously within 2–3 months. Conclusion: MWA is safe, feasible, and effective for the treatment of PHPT.