The migration law of magnesium ions during freezing and melting processes.

To explore the migration law of magnesium ions (Mg2+) during freezing and melting processes, laboratory simulation experiments involving freezing and melting were carried out to investigate the influence of ice thickness, freezing temperature, initial concentration, and initial pH on the distribution of Mg2+ in the ice-water system. The distribution coefficient "K" (the ratio of the Mg2+ concentration in the ice layer to the Mg2+ concentration in the water layer under ice) was used to characterize the migration ability of Mg2+. The results showed that during the freezing process, the concentration distribution of Mg2+ in the ice and water two-phase system was as follows: ice layer < water before freezing < water layer under ice; in other words, it migrated from ice layer to the water layer under ice. "K" decreased with increasing ice thickness, freezing temperature, initial concentration, and initial pH; the higher the ice thickness, freezing temperature, initial concentration, and initial pH were, the higher the migration efficiency of Mg2+ into the water layer under ice was. During the melting process, Mg2+ was released in large amounts (50-60%) at the initial stage (0-25%) and in small amounts (25-100%) uniformly in the middle and later periods. According to the change of Mg2+ concentration in ice melt water, an exponential model was established to predict Mg2+ concentration in ice melt period. The migration law of Mg2+during the freezing and melting process was explained by using first principles. Graphical abstract.

Relationship between microRNA-93-5p and mitochondrial fusion protein-2 in mouse nerve cells subjected to oxygen-glucose deprivation and reoxygenation / 中华麻醉学杂志

Objective:To evaluate the relationship between microRNA-93-5p and mitochondrial fusion protein-2 (Mfn2) in mouse nerve cells subjected to oxygen-glucose deprivation and reoxygenation (OGD/R).Methods:Mouse neuroblastoma cells were cultured in vitro to logarithmic growth phase.Experiment Ⅰ Cells were divided into 5 groups ( n=20 each) by the random number table method: control group (group C), group OGD/R, miR-93-5p inhibitor group (group I), siRNA-mfn2 plus miR-93-5p group (group siMfn2+ I) and miR-93-5p negative control group (group NC). Oxygen-glucose deprivation: the cells were cultured for 3 h in a low-glucose balanced salt solution at 37 ℃ in an environment of 5% CO 2-95% N 2.Restoration of oxygen and glucose: the cells were cultured in normal medium at 37℃ in 5% CO 2-95% air for 24 h. Group I, group siMfn2+ I and group NC were transfected with miR-93-5p inhibitor, miR-93-5p inhibitor plus siRNA-mfn2 and negative control miRNA, respectively, at 48 h before the OGD/R model was developed.Cell viability was measured by CCK-8 assay.Cell apoptosis rate was measured by flow cytometry.Quantitative real-time polymerase chain reaction was used to detect the expression of miR-93-5p and Mfn2 mRNA.Western blot was used to detect Mfn2 protein expression.Experiment Ⅱ The wild-type (WT)-Mfn2 and mutant (MUT)-Mfn2 were constructed and transfected into neuroblastoma cells with miR-93-5p mimic and miR-93-5p blank control (miR-93-5pNC), respectively.The cells were divided into 4 groups ( n=5 each) after 48 h of transfection by the random number table method: miR-93-5p NC-WT-Mfn2 co-transfection group, miR-93-5p mimic-WT-Mfn2 co-transfection group, miR-93-5p NC-MUT-Mfn2 co-transfection group, and miR-93-5p mimic-MUT-Mfn2 co-transfection group.The activity of luciferases was measured by double luciferase assay. Results:Experiment Ⅰ Compared with group C, the cell viability was significantly decreased, the apoptosis rate of cells was increased, the expression of miR-93-5p was up-regulated, and the expression of Mfn2 protein and mRNA was down-regulated in the other gorups ( P<0.05). Compared with group OGD/R or group NC, the cell viability was significantly increased, the apoptosis rate of cells was decreased, miR-93-5p expression was down-regulated, and the expression of Mfn2 protein and mRNA was up-regulated in group I ( P<0.05). Compared with group I, the cell viability was significantly decreased, the apoptosis rate of cells was increased, and the expression of Mfn2 protein and mRNA was down-regulated in group siMfn2+ I ( P<0.05). Experiment Ⅱ Compared with miR-93-5p NC-WT-Mfn2 co-transfection group, the luciferase activity was significantly decreased in miR-93-5p mimic-WT-Mfn2 co-transfection group ( P<0.05). There was no significant difference in luciferase activity between miR-93-5p NC-MUT-Mfn2 co-transfection group and miR-93-5p mimic-MUT-Mfn2 co-transfection group ( P>0.05). Conclusions:The miR-93-5p expression is up-regulated, which further targetedly down-regulates the expression of Mfn2, and this may be a mechanism of OGD/R in mouse nerve cells.

Impacts of electroacupucnture at Zusanli (ST 36) and Feishu (BL 13) on the postoperative inflammatory reaction and pulmonary complications in senile patients after radical resection of pulmonary carcinoma / 中国针灸

<p><b>OBJECTIVE</b>To observe the impacts of electroacupuncture (EA) at Zusanli (ST 36) and Feishu (BL 13) applied 30 min before the operation till the end of the operation on the postoperative inflammatory reaction and pulmonary complications in the senile patients after radical resection of pulmonary carcinoma.</p><p><b>METHODS</b>Eighty senile patients of pulmonary carcinoma were selected and randomized into an observation group and a control group, 40 cases in each one. In the observation group, EA stimulation at Zusanli (ST 36) and Feishu (BL 13) was used 30 min before the operation till the end of the operation. In the control group, electric stimulation was not used. Separately, before operation (T, basic state), 12 h after operation (T) and 24 h after operation (T), blood sample was collected from the central vein. The concentrations of plasma tumor necrosis factor-ɑ (TNF-ɑ) and interleukin-10 (IL-10) were detected. Additionally, the radial arterial blood sample was collected at the above time points; oxygen partial pressure (PaO) was determined; pulmonary alveoli-arterial partial pressure of oxygen (PDO) and oxygenation index (OI) were calculated. The pulmonary complication in the two days after operation was recorded.</p><p><b>RESULTS</b>Compared with the control group, in the observation group, at Tand T, TNF-ɑ concentration and PDOwere lower (all<0.05); plasma IL-10 concentration and OI were higher (all<0.05). In the observation group, the incidences of postoperative pneumonia and acute pulmonary injury were lower than those in the control group (both<0.05).</p><p><b>CONCLUSIONS</b>EA reduces the postoperative inflammatory reaction in the senile patients with radical resection of pulmonary carcinoma and decreases the postoperative pulmonary complicattizen.</p>