Molecular Dynamic Simulation Study on Replacement of Methane Hydrates with Carbon Dioxide Under Different Temperatures, Pressures, and Concentrations of Ethylene Glycol.

In order to alleviate the world energy resources crisis, the research and development of natural gas hydrates has a very important economic value and strategic significance. The CH4-CO2 replacement method can not only achieve geological storage of carbon dioxide but also more effectively mine natural gas hydrates. Based on molecular dynamics theory and the properties of natural gas hydrates, this paper delves into the replacement of methane hydrate with carbon dioxide under different temperatures, pressures, and concentrations of ethylene glycol (EG). We established a CO2-Hydrate model and three CO2/EG-Hydrate models with different concentrations of EG, and we simulated the radial distribution function (RDF), mean square displacement (MSD), and relative density distribution of each particle in the system in different conditions. The higher the temperature, the more unstable the methane hydrates are, and the methane hydrates are more prone to decomposition. Compared with 280 and 290 K, the temperature of 270 K is more favorable for carbon dioxide molecules to enter the hydrate layer and form carbon dioxide hydrates. The changes in pressure have little impact on the decomposition of methane hydrates, the rupture of water cages of methane hydrates, and the number of carbon dioxide molecules entering the hydrate layer under temperatures of 280 K and pressures of 1, 4, and 7 MPa. But overall, a pressure of 1 MPa is more conducive for carbon dioxide molecules to enter the hydrate layer and form carbon dioxide hydrates. Adding EG to CO2 molecules can inhibit the decomposition of methane hydrates. However, the higher the concentration of EG, the faster the decomposition of methane hydrates. The degree of fracture of the water cages in methane hydrates is greater under pure CO2 conditions. Adding EG to CO2 molecules is more conducive for CO2 molecules to enter the hydrate layer and form carbon dioxide hydrates. This review is of great significance to improve the mining efficiency and CO2 storage efficiency of the replacement of natural gas hydrates with CO2.

Metformin relieves H/R-induced cardiomyocyte injury through miR-19a/ACSL axis - possible therapeutic target for myocardial I/R injury.

This study proposed to investigate the function of miR-19a/ACSL axis in hypoxia/reoxygenation (H/R)-induced myocardial injury and determine whether metformin exerts its protective effect via miR-19a/ACSL axis. Firstly, bioinformatics analysis of data from Gene Expression Omnibus (GEO) database indicated that miR-19a was downregulated in patients with myocardial infarction (MI) compared to that in control group. H/R model was constructed with AC16 cells in vitro. qRT-PCR assay revealed that miR-19a was downregulated in H/R-treated AC16 cells. Then, CCK-8 assay demonstrated that upregulation of miR-19a significantly alleviated H/R-induced decline of cell viability. Moreover, bioinformatics prediction, western blotting and dual-luciferase reporter assays were performed to check the target genes of miR-19a, and ACSL1 was determined as a downstream target gene of miR-19a. Besides, the analysis based on Comparative Toxicogenomics Database (CTD) suggested that metformin targeting ACSL1 can be used as a potential drug for further research. Biological function experiments in vitro revealed that H/R markedly declined the viability and elevated the apoptosis of AC16 cells, while metformin can significantly mitigate these effects. Furthermore, overexpression of miR-19a significantly strengthened the beneficial effect of metformin on H/R-induced AC16 cells injury, which can be reversed by upregulation of ACSL1. In conclusion, metformin can alleviate H/R-induced cells injury via regulating miR-19a/ACSL axis, which lays a foundation for identifying novel targets for myocardial I/R injury therapy.

Retrospective study of the prognostic significance of neutrophil-to-lymphocyte ratio for postsurgical outcomes of patients with endometrial carcinoma.

OBJECTIVE: To evaluate the significance of postoperative inflammatory system response markers in predicting the prognosis of patients with endometrial cancer undergoing surgery. METHODS: The present retrospective study included patients who underwent surgical treatment for pathology-confirmed endometrial cancer between January 1, 2007, and June 30, 2013, at the Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China. Potential prognostic factors were investigated by Cox proportional hazards analysis and survival rates were compared using Kaplan-Meier analyses. RESULTS: There were 185 patients with surgically treated endometrial cancer included. Multivariate analyses demonstrated that a preoperative neutrophil-to-lymphocyte ratio (NLR) above 1.81 (P=0.010) and a postoperative NLR above 7.54 (P=0.008) were both independently associated with lower disease free survival. Elevated preoperative and postoperative NLRs were associated with higher tumor stage (P=0.021 and P=0.009, respectively), and only elevated preoperative NLR was associated with lymph node involvement (P=0.023). CONCLUSION: Preoperative and postoperative NLRs were independently associated with inflammatory system response markers and could be combined to evaluate the prognosis of patients with endometrial cancer following surgery.

[Bone density in osteoarthritic femoral heads: quantitative assessment by histomorphologic and histomorphometric analysis].

OBJECTIVE: To determine whether bone density is related to osteoarthritis and to compare osteoarthritis with osteoporotic fracture of the femoral neck. METHODS: All 165 femoral heads removed at joint replacement surgery were divided into 4 groups according to radiographic features of hip (osteophytes, subchondral sclerosis, cysts and femoral head deformity). The individual femoral head was divided into 5 zones histologically. Sections were studied histomorphologically, and quantitation was performed using the computer-assisted system to determine the bone density of the femoral head. RESULTS: The values of bone density in weight-bearing, super lateral non weight-bearing (SL) and inferior medial non weight-bearing (IM) areas after femoral neck fracture in patients with osteoarthritis were lower than normal. The values of bone density in weight bearing area were increased in patients with osteoarthritis in all four groups but lower than normal in one group (I), and higher than normal in other 2 groups (III, IV). The values of bone density in SL and IM areas except IM area in group IV were lower than normal (P > 0.05). The values of bone density in the central area in the 4 groups were relatively consistent and normal. The density of Haversian canals was increased in the 4 groups indicating osteoporosis of the femoral head. The average age of patients with femoral neck fracture associated with OA (group I) was significantly higher than that of group II, III, IV (P < 0.05). CONCLUSIONS: Bone density is different in the femoral head and neck. Dividing the weight bearing joint into distinct zones is a method for laboratory and clinical study. Femoral neck fracture associated with OA was caused by osteoporosis which is related to the age of the patient. The data of this study can be regarded as a potential indicator of implant/host bone relations with morphological, morphometric implications.