7 results on '"Xiaofeng Zhou"'
Search Results
2. Experimental investigation of long-term fracture conductivity filled with quartz sand: Mixing proppants and closing pressure.
- Author
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Jianguang, Wei, Xiaofeng, Zhou, Xiaofei, Fu, Yinghe, Chen, and Fan, Bu
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PROPPANTS , *HYDRAULIC fracturing , *SIZE reduction of materials , *PETROLEUM reservoirs - Abstract
With the rapid technological advances in hydraulic fracturing, the economic development of ultra-tight gas/oil reservoirs becomes feasible, altering current energy image between demand and supply. The key parameter evaluating the artificial hydraulic fracture is the long-term conductivity, manifesting the transport capacity for reservoir fluids. The majority of previous contributions focused on the impacts of inherent proppant properties on long-term fracture conductivity, while the influence induced by mixture proppants with a wide range of particle size has not received due attention. In particular, as for the realistic field case, multiple types of proppants with diverse particle sizes are utilized to reach desirable conductivity. At the same time, the stress conditions inevitably change within the depressurization development process, leading to the evident enhancement of closing pressure towards artificial fracture, acting as the detrimental role for long-term fracture conductivity. As a result, it is dramatically necessary and urgent to reveal the mutual influence arising from mixture proppants as well as closing pressure. In order to address this issue, series of laboratory experiments are implemented, and comprehensive theoretical analysis in terms of experimental data is performed. Results show that (a) reduction of particle size is observed with increasing closing pressure, the average decreasing rate approaches 19.3%; (b) Closing pressure acts as a detrimental role impairing conductivity, the amplitude is able to reach 42.1% as for the mixture case with a relatively high proportion of mesh-20/40 particles; (c) Mixing proppants uniformly fails to enhance fracture conductivity effectively, and the forward segmentation is demonstrated as the suitable strategy and beneficial for fluid transport capacity. The contribution expects to advance current understanding regarding the impact of mixture proppants on long-term fracture conductivity. • Laboratory experiments are implemented to examine long-term fracture conductivity. • Multiple factors are investigated, including closing pressure, mixture ratio, as well as mixture strategy. • Mixing proppants uniformly fails to enhance fracture conductivity effectively. • Decreasing amplitude reaches 42.1% as for relative high proportion of mesh-20/40 particles. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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3. The influence of cosurfactants on the synthesis of hierarchically porous silica materials in a P123/cosurfactant/1,3,5-trimethylbenzene/water four-component microemulsion system.
- Author
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Xiaofeng Zhou, Aijun Duan, Zhen Zhao, Yanjun Gong, Huadong Wu, Yuechang Wei, Guiyuan Jiang, and Jian Liu
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SURFACE active agents , *POROUS silica synthesis , *TOLUENE , *MICROEMULSIONS , *ETHYLENE glycol , *AMORPHOUS substances - Abstract
This research reported a micelle/microemulsion bimodal templating method to synthesize hierarchical porous silicas (HPS) by using a P123/cosurfactant/1,3,5-trimethylbenzene/water four-component microemulsion system. The influence of different diols (i.e., ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentadiol, and 1,6-hexanediol) as cosurfactants on the synthesis of HPS was systematically investigated. Among the obtained mesoporous silica materials, the HPS materials with pore structures of disordered-SBA-15-type (Dis-SBA-15) together with mesocellular foams (MCFs) could be clearly identified from the TEM images when using ethanediol, 1,3-propanediol, or 1,4-butanediol as the swelling agent of P123 in the initial synthesis environment, while MCFs were the main phases as using 1,5-pentadiol and 1,6-hexanediol. The results showed that those shorter chain diols with carbon number from 2 to 4 (involving ethanediol, 1,3-propanediol, and 1,4-butanediol) could more easily swell the P123 micelles compared with the longer chain diols (1,5-pentadiol and 1,6-hexanediol). Consequently, HPS materials with large pore volumes (up to 1.48 cm³ g-1) were successfully prepared by the oriented role from the templates of the swollen P123 micelles and TMB/P123 microemulsions. This approach provides a novel pathway for the facile synthesis of HPS materials with large pore volumes which may be a type of promising candidate for various applications. [ABSTRACT FROM AUTHOR]
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- 2014
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4. Global Expression-Based Classification of Lymph Node Metastasis and Extracapsular Spread of Oral Tongue Squamous Cell Carcinoma.
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Xiaofeng Zhou, Temam, Stephane, Myungshin Oh, Pungpravat, Nisa, Bau-Lin Huang, Li Mao, and Wong, David T.
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SQUAMOUS cell carcinoma , *LYMPH node cancer , *METASTASIS , *BIOMARKERS , *GENE expression - Abstract
Regional lymph node metastasis is a critical event in oral tongue squamous cell carcinoma (OTSCC) progression. The identification of biomarkers associated with the metastatic process would provide critical prognostic information to facilitate clinical decision making for improved management of OTSCC patients. Global expressional profiles were obtained for 25 primary OTSCCs, where 11 cases showed lymph node metastasis (pN+) histologically and 14 cases were non-metastatic (pN-). Seven of pN+ cases also exhibited extracapsular spread (ECS) of metastatic nodes. Multiple expression indices were used to generate signature gene sets for pN +/- and ECS+/- cases. Selected genes from signature gene sets were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The classification powers of these genes were then evaluated using a logistic model, receiver operating characteristic curve analysis, and leave-one-out cross-validation. qRT-PCR validation data showed that differences at RNA levels are either statistically significant (P < .05) or suggestive (P < .1) for six of eight genes tested (BMP2, CTTN, EEF1A1, GTSE1, MMP9, and EGFR) for pN+/- cases, and for five of eight genes tested (BMP2, CTTN, EEF1A1, MMP9, and EGFR) for ECS+/- cases. Logistic models with specific combinations of genes (CTTN+MMP9+EGFR for pN and CTTN+EEF1A1+MMP9 for ECS) achieved perfect specificity and sensitivity. Leave-one-out cross-validation showed overall accuracy rates of 85% for both pN and ECS prediction models. Our results demonstrated that the pN and the ECS of OTSCCs can be predicted by gene expression analyses of primary tumors. [ABSTRACT FROM AUTHOR]
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- 2006
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5. Bioequivalue of two mycophenolate sodium enteric-coated tablets and the drug monitoring based on limited sampling strategy: A single-center, randomized, open-label, three-period, reference-replicated, crossover study.
- Author
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Guangxun Xu, Zhendi Wang, Tianzhong Yan, Jinyu Li, and Xiaofeng Zhou
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ENTERIC-coated tablets , *DRUG tablets , *DRUG monitoring , *MYCOPHENOLIC acid , *SODIUM , *FEEDING tubes , *TUBE feeding - Abstract
Objective: A mycophenolate sodium enteric-coated tablet has shown a satisfying anti-rejection effect in patients receiving solid organ transplantation. The current study evaluated the bioequivalence between the test (Ruiyirong®) vs. reference (Myfortic®) formulations by exploring equations for predicting their area under the concentration-time curve (AUC) using a limited sampling strategy in healthy subjects. Methods: Forty-eight healthy Chinese subjects were randomized into three administration sequences (testreference-reference, reference-reference-test, and reference-test-reference) to receive the Ruiyirong or Myfortic treatment on days I, 8, and 15. Results: The 90% confidential interval (Cl) of the geometric mean ratios (tesl/reference) of maximum plasma concentration (Cmax), the AUC from lime 0 to the last timepoint (AUCo,), and the AUC from 0 to infinity (AUCo-oo) was 92.90%-l 10.57%, 96.91%-101.80%, and 96.71 %-10l .84%, respectively. All these values fell into the bioequivalence criteria of 80.00%-125.00% (based on the criteria of the Food and Drug Administration). The adverse events were 10.4% in Ruiyirong test group and 14.6% in Myfortic reference group. Eight equations for estimating the AUC of the Ruiyirong test and Myfortic reference formulations were evaluated; most of them worked well with the R-value >0.8. Among the four chosen equations, the intragroup verification exhibited a high agreement with the R-value ranging from 0.857 to 0.971 and with the low predictive error (PE 5% with absolute PE > 15%). Meanwhile, the intergroup verification indicated a high inter-agreement with the R-value ranging from 0.896 to 0.974 (all P < 0.001). Conclusion: The Ruiyirong test vs. Myfortic reference formulations meet the bioequivalent criteria and are well tolerated. The further linear regression analysis explores eight equations predicting the AUC value and the chosen four equations for the Ruiyirong test and Mayfortic reference formulations are interchangeable. [ABSTRACT FROM AUTHOR]
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- 2023
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6. Molecular Characterization of the MicroRNA-138-Fos-like Antigen 1 (FOSL1) Regulatory Module in Squamous Cell Carcinoma.
- Author
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Yi Jin, Cheng Wang, Xiqiang Liu, Wenbo Mu, Zujian Chen, Dongsheng Yu, Anxun Wang, Yang Dai, and Xiaofeng Zhou
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MESSENGER RNA , *ANTIGENS , *SQUAMOUS cell carcinoma , *PROTO-oncogenes , *CADHERINS - Abstract
MicroRNA-138 is one of the most frequently down-regulated microRNAs in cancer. We recently identified 51 candidate targets of microRNA-138 (Jiang, L., Dai, Y., Liu, X., Wang, C., Wang, A., Chen, Z., Heidbreder, C. E., Kolokythas, A., and Zhou, X. (2011) Hum. Genet. 129, 189-197). Among these candidates, Fos-like antigen 1 (FOSL1) is a member of Fos gene family and is a known proto-oncogene. In this study, we first confirmed the microRNA-138-mediated down-regulation of FOSL1 in squamous cell carcinoma cell lines. We then demonstrated the effect of this microRNA-138-FOSL1 regulatory module on downstream genes (homolog of Snail 2 (Snai2) expression and the Snai2-mediated repression of E-cadherin expression), as well as its contributions to tumorigenesis. The microRNA-138-directed recruitment of FOSL1 mRNA to the RNAi-induced silencing complex was confirmed by a ribonucleoprotein-immunoprecipitation assay. Three canonical and three high affinity non-canonical microRNA-138 (miR-138) targeting sites were identified on the FOSL1 mRNA: one in the 5′-UTR, three overlapping sites in the coding sequences, and two overlapping sites in the 3′-UTR. The direct targeting of miR-138 to these sites was confirmed using luciferase reporter gene assays. In summary, we describe an important microRNA regulatory module, which may play an important role in cancer initiation and progression. Our results also provide evidence that microRNAs target both canonical and non-canonical targeting sites located in all areas of the mRNA molecule (e.g. 5′-UTR, coding sequences, and 3′-UTR). [ABSTRACT FROM AUTHOR]
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- 2011
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7. Candidate Tumor-Suppressor Gene DLEC1 Is Frequently Downregulated by Promoter Hypermethylation and Histone Hypoacetylation in Human Epithelial Ovarian Cancer.
- Author
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Kwong, Joseph, Ji-Young Lee, Kwong-Kwok Wong, Xiaofeng Zhou, Wong, David T. W., Kwok-Wai Lo, Welch, William R., Berkowitz, Ross S., and Mok, Samuel C.
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CANCER treatment , *OVARIAN tumors , *CANCER cells , *CELL culture , *CELL lines , *METHYLATION , *CELL nuclei - Abstract
Suppression of ovarian tumor growth by chromosome 3p was demonstrated in a previous study. Deleted in Lung and Esophageal Cancer 1 (DLEC1) on 3p22.3 is a candidate tumor suppressor in lung, esophageal, and renal cancers. The potential involvement of DLEC1 in epithelial ovarian cancer remains unknown. In the present study, DLEC1 downregulation was found in ovarian cancer cell lines and primary ovarian tumors. Focus-expressed DLEC1 in two ovarian cancer cell lines resulted in 41% to 52% inhibition of colony formation. No chromosomal loss of chromosome 3p22.3 in any ovarian cancer cell line or tissue was found. Promoter hypermethylation of DLEC1 was detected in ovarian cancer cell lines with reduced DLEC1 transcripts, whereas methylation was not detected in normal ovarian epithelium and DLEC1-expressing ovarian cancer cell lines. Treatment with demethylating agent enhanced DLEC1 expression in 90% (9 of 10) of ovarian cancer cell lines. DLEC1 promoter methylation was examined in 13 high-grade ovarian tumor tissues with DLEC1 downregulation, in which 54% of the tumors showed DLEC1 methylation. In addition, 80% of ovarian cancer cell lines significantly upregulated DLEC1 transcripts after histone deacetylase inhibitor treatment. Therefore, our results suggested that DLEC1 suppressed the growth of ovarian cancer cells and that its downregulation was closely associated with promoter hypermethylation and histone hypoacetylation. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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