Epikarst water detection using integrated geophysical methods.

When detecting epikarst water using the self-potential method, the actual location of the anomaly center often deviates from the prospecting result due to the interference of the regional background field, which is comprised of geological noise and artificial electromagnetic fields. Ultimately, this makes it difficult to locate the detection target accurately. To address the potential offset of the anomaly center location, in this study we introduce the differential filtering method into the data processing procedure. This method has smoothing and low-pass filtering effects, facilitating the extraction of meaningful anomalies. Meanwhile, based on the anomalous features of different physical parameters, we propose an integrated method system based on differentially filtered horizontal self-potential gradient data, the composite profile method, and the high-density electrical method, which can effectively improve the accuracy of anomaly localization. This newly established method system was applied at the Xiaguantun test site in Longzhou County, Chongzuo, Guangxi Province, China, and its effectiveness and feasibility was confirmed.

Isolation of a Novel Anti-Diabetic α-Glucosidase Oligo-Peptide Inhibitor from Fermented Rice Bran.

At present, the incidence rate of diabetes is increasing gradually, and inhibiting α-glucosidase is one of the effective methods used to control blood sugar. This study identified new peptides from rice bran fermentation broth and evaluated their inhibitory activity and mechanism against α-glucosidase. Rice bran was fermented with Bacillus subtilis MK15 and the polypeptides of <3 kDa were isolated by ultrafiltration and chromatographic column, and were then subjected to LC-MS/MS mass spectrometry analysis. The results revealed that the oligopeptide GLLGY showed the greatest inhibitory activity in vitro. Docking studies with GLLGY on human α-glucosidase (PDB ID 5NN8) suggested a binding energy of −7.1 kcal/mol. GLLGY acts as a non-competitive inhibitor and forms five hydrogen bonds with Asp282, Ser523, Asp616, and His674 of α-glucosidase. Moreover, it retained its inhibitory activity even in a simulated digestion environment in vitro. The oligopeptide GLLGY could be developed into a potential anti-diabetic agent.

Virgibacillus halodenitrificans ST-1 for fermentation of shrimp paste and hydrolysates of its protease.

The nutrition and flavor of shrimp paste came from hydrolyzation by enzymes that were produced by microorganisms. The salt-tolerant strain Virgibacillus halodenitrificans ST-1 isolated from shrimp paste was studied and used in the fermentation of shrimp paste. The strain and the protease produced by ST-1 were investigated. The optimum pH of the protease was 8.0, and the reaction temperature was 30°C. The protease showed high activity in the range of pH (5.0-11.0) and NaCl concentration (1%-15%). Divalent cations such as Ba2+, Ca2+, Mg2+, Mn2+, and Si2+ could enhance the protease activity. Residual activity of protease was more than 90% when it was incubated with PMSF and H2O2. Also, the enzyme retained more than 90% of initial activity after it was incubated with organic solvents. Variety of natural proteins could be substrates of the protease. By analyzing the release rate of free amino acids, it was predicted that the cleavage sites of the protease were mainly Glu, Asp, Gly, Leu, and Lys. Moreover, the hydrolysates of the protease had antioxidant activity, especially for DPPH and superoxide anion radical scavenging. The strain ST-1 and the protease both were excellent candidates for food industries.

Expression, purification and characterization of a cold-adapted dextranase from marine bacteria and its ability to remove dental plaque.

Dental plaque is a high-incidence health concern, and it is caused by Streptococcus mutans. Dextranase can specifically hydrolyze ɑ-1,6-glycosidic linkages in dextran. It is commonly used in the sugar industry, in the production of plasma substitutes, and the treatment and prevention of dental plaque. In this research work, we successfully cloned and expressed a cold-adapted dextranase from marine bacteria Catenovulum sp. DP03 in Escherichia coli. The recombinant dextranase named Cadex2870 contained a 2511 bp intact open reading frame and encoded 836 amino acids. The expression condition of recombinant strain was 0.1 mM isopropylthio-galactoside (IPTG), and the reduced temperature was 16 °C. The purified enzyme activity was 16.2 U/mg. The optimal temperature and pH of Cadex2870 were 45 °C and pH 8, and it also had catalytic activity at 0 °C. The hydrolysates of Cadex2870 hydrolysis Dextran T70 are maltose, maltotetraose, maltopentose, maltoheptaose and higher molecular weight maltooligosaccharides. Interestingly, 0.5% sodium benzoate, 2% xylitol, 0.5% sodium fluoride, 5% propanediol, 5% glycerin and 2% sorbitol can enhance stability Cadex2870, which are additives in mouthwashes. Additionally, Cadex2870 reduced the formation of dental plaque and effectively degraded formed plaque. Therefore, Cadex2870 shows great promise in commercial applications.

The Marine Catenovulum agarivorans MNH15 and Dextranase: Removing Dental Plaque.

Dextranase, a hydrolase that specifically hydrolyzes α-1,6-glucosidic bonds, has been used in the pharmaceutical, food, and biotechnology industries. In this study, the strain of Catenovulum agarivorans MNH15 was screened from marine samples. When the temperature, initial pH, NaCl concentration, and inducer concentration were 30 °C, 8.0, 5 g/L, and 8 g/L, respectively, it yielded more dextranase. The molecular weight of the dextranase was approximately 110 kDa. The maximum enzyme activity was achieved at 40 °C and a pH of 8.0. The enzyme was stable at 30 °C and a pH of 5-9. The metal ion Sr2+ enhanced its activity, whereas NH4+, Co2+, Cu2+, and Li+ had the opposite effect. The dextranase effectively inhibited the formation of biofilm by Streptococcus mutans. Moreover, sodium fluoride, xylitol, and sodium benzoate, all used in dental care products, had no significant effect on dextranase activity. In addition, high-performance liquid chromatography (HPLC) showed that dextran was mainly hydrolyzed to glucose, maltose, and maltoheptaose. The results indicated that dextranase has high application potential in dental products such as toothpaste and mouthwash.

Efficacy of Renshen Sanqi Chuanxiong formula for preventing vascular aging.

OBJECTIVE: To evaluate the efficacy of Renshen Sanqi Chuanxiong formula (RSCF) for preventing vascular aging, and to investigate the possible molecular mechanism underlying the actions of RSCF. METHODS: Potentially active components and their relatively direct targets were identified by combining drug-likeness (DL) screening using a target identification process. Vascular aging-associated targets for RSCF were obtained by selecting common genes not only from potential targets but also from human vascular aging-associated genes. Cytoscape 3.2.1 software was employed to visualize the complex compound-target and target-function networks. Biological process and molecular function were assessed, and the Kyoto Encyclopedia of Genes and Genomes and pathway enrichment analyses were performed using ClueGO. Pathways directly associated with vascular aging were integrated into a ""vascular aging-related"" pathway. RESULTS: Altogether, 122 potentially active components of RSCF were identified through DL screening, and their corresponding 692 direct targets were retrieved via target prediction and identification. We identified 49 vascular aging-associated targets for RSCF by overlapping the 692 potential targets with 146 human vascular aging-associated genes. The results from the compound-target network indicated that most components acted on common targets and displayed synergistic action, which showed that the magnifying effects of RSCF were based on these common targets. The target-function network revealed that each target was involved in multiple function modules, suggesting that RSCF was multi-functional during treatment of vascular aging. The results of the ClueGO analysis indicated that most of the targets were associated with the hypoxia-inducible factor 1 (HIF-1) signaling pathway. The results from the pathway analysis also indicated that an integrative vascular aging-related pathway mainly included an angiogenesis regulation module, cell-survival module, and oxidative stress-resistance module. CONCLUSION: Our results suggested that many components act synergistically on common targets to delay vascular aging, and each target is involved in multiple functional modules. The ClueGO analysis indicated that most of the targets were connected to the HIF-1 signaling pathway, FOXO signaling pathway, and thyroid hormone signaling pathway.

[Effect of microRNA-34a/SIRT1/p53 signal pathway on notoginsenoside R1 delaying vascular endothelial cell senescence].

This study aimed to investigate the effect of notoginsenoside R1 in delaying H2O2-induced vascular endothelial cell senescence through microRNA-34a/SIRT1/p53 signal pathway. In this study， human umbilical vein endothelial cells(HUVECs) were selected as the study object; the aging model induced by hydrogen peroxide(H2O2) was established， with resveratrol as the positive drug. HUVECs were randomly divided into four groups， youth group， senescence model group， notoginsenoside R1 group and resveratrol group. Notoginsenoside R1 group and resveratrol group were modeled with 100 µmoL·L⁻¹ H2O2 for 4 h after 24 h treatment with notoginsenoside R1(30 µmoL·L⁻¹) and resveratrol(10 µmoL·L⁻¹) respectively. At the end， each group was cultured with complete medium for 24 h. The degree of cellular senescence was detected by senescence-associated ß-galactosidase(SA-ß-Gal) staining kit， the cell viability was detected by cell counting kit-8， the cell cycle distribution was analyzed by flow cytometry， and the cellular SOD activity was detected by WST-1 method in each group. The expressions of SIRT1， p53， p21 and p16 proteins in HUVECs were detected by Western blot. In addition， the mRNA expressions of miRNA-34a， SIRT1 and p53 in HUVECs were assayed by Real-time PCR. These results indicated that notoginsenoside R1 significantly reduced the positive staining rate of senescent cells， enhanced the cell proliferation capacity and intracellular SOD activity， decreased the proportion of cells in G0/G1 phase， and increased the percentage of cells in S phase simultaneously compared with the senescence model group. Moreover， notoginsenoside R1 decreased the mRNA expressions of miRNA-34a and p53 and the protein expression of p53， p21 and p16.At the same time， notoginsenoside R1 increased the protein and mRNA expressions of SIRT1. The differences in these results between the senescence model group and the notoginsenoside R1 group were statistically significant(P<0.05). However， there was not statistically significant difference in these results between the notoginsenoside R1 group and the resveratrol group. In conclusion， the senescence of endothelial cells induced by H2O2 can be used as a model for studying aging. Notoginsenoside R1 has an obvious anti-aging effect on vascular endothelial cells in this study. The possible mechanism is that notoginsenoside R1 can delay the senescence process of vascular endothelial cells induced by H2O2 by regulating microRNA-34a/SIRT1/p53 signal pathway.

[Effect of body fat distribution on plasma lipids and oxidative stress in women aged 35 to 50 years].

OBJECTIVE: To evaluate the effect of body fat composition and distribution on plasma lipid profile and oxidative stress in middle-aged women. METHODS: 181 healthy Chinese women (age ranged from 35 to 50 years) were recruited. Their body fat mass and distribution were measured by dual-energy x-ray absorptiometry (DEXA). The oxidative status were evaluated by determination of serum levels of tumor necrosis factor-alpha (TNF-alpha), Glutathione peroxidase (GR) and Superoxide dismutase (SOD) and the plasma lipids, including total cholesterol (TC) and Triglycerides (TG) were also measured. RESULTS: (1) Plasma TG and TC levels and serum TNF-alpha levels were significantly higher in overweight and obese women, while serum SOD and GR activity were significantly in these 2 groups, compared to normal-weight women. (2) Serum SOD and GR activity decreased, and TNF-alpha level increased with body mass index (BMI) and abdominal fat mass, as shown by linear correlation analysis. No correlation was found between serum oxidative indices, lipids and total body and subcutaneous fat. (3) The percentage of abdominal fat mass had positive correlations with the SOD and GR, and negative correlations with TNF-alpha. Whereas the percentage of subcutaneous fat mass did not have correction relationship with TNF-alpha, SOD, GR, but had negative correlation with TG and TC. (4) By the partial correlations analysis, abdominal fat mass were found to be negatively correlated with serum SOD and GR, and positively correlated with serum TNF-alpha. CONCLUSION: Abdominal fat accumulation could be the marker of the oxidative stress and would elevate serum triglycerides and total cholesterols.

[Study on calcium absorption rate in premenarche Chinese girls aged 9 - 11.5 years].

OBJECTIVE: To investigate the characteristics of calcium metabolism in relation to different levels of dietary calcium intakes in premenarche Chinese girls. METHODS: Forty-nine healthy premenarche girls of Han ethic (9 - 11.5 years) were recruited, and divided into four groups respectively, receiving four different doses of calcium intakes for 6 days, 600 mg (usual diet), 900 mg (containing 250 ml of milk), 1200 mg (containing 250ml of milk and 750 mg of calcium carbonate) and 1500mg calcium (250 ml of milk and 1500 mg of calcium carbonate) per day. A 3-day urine and stool, and a 3-d duplicated food samples were collected to assess the calcium excretion in urine and feces and input of the dietary calcium during the treatment period. RESULTS: There were no significant differences in appearance calcium absorption among the four groups (55%, 53%, 52% and 52%). Urine calcium is correlated negatively with dietary protein and dietary phosphorus. And no correlation was found between dietary protein and calcium absorption. CONCLUSION: The appearance calcium absorption was (53 +/- 0.12) % in Chinese premenarche girls with dietary calcium intakes ranged between 800 to 1600 mg/d, high dietary protein intakes increase urine calcium secrete.