Investigation on Actuating Pressure Gradient of Low Permeability Reservoir

Due to the presence of actuating pressure of low permeability reservoir, researching on actuating pressure gradient of low permeability reservoir is necessary. While actuating pressure gradient is relevant to permeability and porosity, it can be obtained through laboratory experiments, well testing interpretation method and theory derivation combined with practical application method. The results of a large number of laboratory experiments show that actuating pressure is related to permeability. The greater the permeability is, the smaller the actuating pressure is. They both present the similar hyperbolic relationship; the greater the viscosity of the oil is, the greater the actuating pressure is. Here, we get the actuating pressure gradient formula through the method of theory derivation combined with practical application, meanwhile we put forward the relationship between actuating pressure gradient and permeability, porosity and viscosity.Key words: Low permeability reservoir; Actuating pressure gradient; Porosity; Fluid viscosit

Water Drive Characteristic Curve Theory of Low Permeability Reservoir

The so-called water flooding characteristic curve refers to the oilfield water injection (or natural water drive) development process, a relationship between curve cumulative oil production, cumulative water production and accumulation of fluid production. These curves have been widely used for water injection development of dynamic and recoverable reserves forecast. After many years of practical application, summed up the four kinds of water drive characteristic curve, they have a good practical significance. Recoverable reserves are important indicators of field development and also the main basis for planning and design, while the application of water flooding characteristic curve can be predicted oil recoverable reserves. Four kinds of water flooding characteristics discussed above curve are mainly applied in high-permeability oil field, which did not consider starting pressure. In fact we should consider the impact of low permeability oilfield actuating pressure gradient on the water content. Here, we deduce the formulation considering the actuating pressure.Key words: Low permeability; Water flooding; Actuating pressur

Protective effect of maternal exposure to α-lipoic acid during pregnancy and lactation on susceptibility to OVAinduced neonatal asthma

Purpose: To investigate the beneficial effect of alpha-lipoic acid (ALA) during pregnancy and lactation on susceptibility to ovalbumin (OVA)-induced neonatal asthma, and the mechanism of involved.Methods: Pregnant BALB/c mice were administered ALA (1 % mixed with mouse chow) or standard mouse chow from 6th day of gestation to 21st day of lactation (postnatal). The offspring (neonatal pups) from the OVA and ALA+OVA groups were sensitized on 1st, 7th and 14th postnatal days (PNDs) via intraperitoneal (i.p.) injection of OVA (0.5 μg). Control mice pups were not exposed to OVA. On PND 21, all pubs were again exposed to 1 % OVA aerosol using a nebulizer.Results: Neonatal mice exposed to ALA showed a significant decline (p < 0.05) in the number of inflammatory cells (eosinophils), levels of inflammatory markers (IL-4, IL-13, IL-5 and TNF-α) as well as OVA-specific IgE and total IgE, when compared to neonatal mice from pregnant mice that did not receive ALA (control). Moreover, the antioxidant profiles of ALA-treated mice offspring were significantly improved (p < 0.05). Marked downregulation (p < 0.05) of the protein expressions of NF-κB p-p65 subunit and TNF-α were observed in ALA-treated mice pups.Conclusion: ALA exposure during pregnancy (maternal exposure) markedly decreases OVA-induced asthmatic airway inflammatory response in pups. Thus, ALA might be beneficial for use along with standard anti-asthmatic drugs in the management of pediatric asthmatic patient

Claudin-1 Is a Valuable Prognostic Biomarker in Colorectal Cancer: A Meta-Analysis

Background. Claudin-1 plays an important part in maintaining the mucosal structures and physiological functions. Several studies showed a relationship between claudin-1 and colorectal cancer (CRC), but its prognostic significance is inconsistent. This meta-analysis assessed the prognostic value and clinical significance of claudin-1 in CRC. Materials and Methods. We retrieved eligible studies from PubMed, Cochrane Library, Embase, and Web of Science databases before February 10, 2020. The hazard ratio (HR) with 95% confidence interval (CI) was applied to assess the correlation between claudin-1 and prognosis and clinical features. Heterogeneity was assessed by the Cochran Q test and I-square (I2), while publication bias was evaluated by the Begg test and Egger test. Test sequence analysis (TSA) was used to estimate whether the included studies’ number is sufficient. The stability of the results was judged by sensitivity analysis. Metaregression was utilized to explore the possible covariance which may impact on heterogeneity among studies. Results. Eight studies incorporating 1704 patients met the inclusion criteria. Meta-analysis showed that the high expression of claudin-1 was associated with better overall survival (HR, 0.46; 95% CI, 0.28–0.76; P=0.002) and disease-free survival (HR, 0.44; 95% CI, 0.29–0.65; P=0.003) in CRC. In addition, we found that claudin-1 was related to the better tumor type (n=6; RR, 0.60; 95% CI, 0.49–0.73; P<0.00001), negative venous invasion (n=4; RR, 0.81; 95% CI, 0.70–0.95; P=0.001), and negative lymphatic invasion (n=4; RR, 0.83; 95% CI, 0.74–0.92; P=0.0009). Conclusion. The increased claudin-1 expression in CRC is associated with better prognosis. In addition, claudin-1 was related to the better tumor type and the less venous invasion and lymphatic invasion

Prognostic Value of MUC2 Expression in Colorectal Cancer: A Systematic Review and Meta-Analysis

Background. The reliability of MUC2 as a prognostic marker in colorectal cancer (CRC) is controversial. This study evaluated the association between MUC2 expression levels in CRC tissues and prognosis. Methods. The PubMed, Web of Science, Embase, Cochrane Library, China Biology Medicine disc (CBMdisc), Wanfang Database, and China National Knowledge Infrastructure (CNKI) databases were searched to identify studies exploring the relationship between MUC2 expression in CRC tissues and overall survival (OS). Pooled hazard ratios (HRs) and risk ratios (RRs) with 95% confidence intervals (CIs) were used to evaluate the associations between MUC2 expression levels and prognosis and MUC2 expression levels and CRC clinicopathological characteristics, respectively. Results. The meta-analysis included 11 studies (2619 patients). Low MUC2 expression level was significantly associated with poor OS (HR, 1.67; 95% CI, 1.43–1.94; P<0.00001) and disease-free survival (DFS)/recurrence-free survival (RFS) (HR, 1.60; 95% CI, 1.21–2.12; P=0.001) in patients with CRC. Low MUC2 expression level was associated with advanced TNM stage (RR, 1.42; 95% CI, 1.26–1.60; P<0.00001), lymph node metastasis (RR, 1.41; 95% CI, 1.25–1.60; P<0.00001), lymphatic invasion (RR,1.64; 95% CI, 1.26–2.12; P=0.0002), rectal tumor site (RR, 1.26; 95% CI, 1.09–1.46; P=0.001), and large tumor size (RR,1.32; 95% CI, 1.02–1.70; P=0.03). There were no associations between low MUC2 expression level and gender, histological grade, depth of invasion, and distant metastasis. Conclusion. The low levels of MUC2 in CRC tissues are poor prognostic factor independent of stage or other well-recognized markers of later-stage disease. Large well-designed cohort studies are required to validate MUC2 as a biomarker for poor prognosis in CRC