Dunaliella salina microalga pressurized liquid extracts as potential antimicrobials

In the present work, the antimicrobial activity of different pressurized liquid extracts obtained from Dunaliella salina microalga was tested against several microorganisms of importance for the food industry (Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus niger). Different solvents (hexane, petroleum ether, hexane, and water) and extraction conditions (40, 100, and 160 degrees C) were tested. Results showed that the best antimicrobial activity was obtained for each solvent at the highest extraction temperature (160 degrees C). Likewise, the extraction yield followed the same trend, i.e., increasing with extraction temperature and was at a maximum when ethanol was used as an extraction solvent. Water extracts had the lowest extraction yields. In general, the best results in terms of antimicrobial activity were obtained using petroleum ether and hexane, although ethanolic extracts also showed good antimicrobial activity. Because the main antimicrobial activity of the extracts was against bacteria, the extracts can be considered to be specifically antibacterial. The extracts were analyzed by gas chromatography-mass spectrometry in order to identify the compounds responsible for activity. Fifteen different volatile compounds as well as several fatty acids (mainly palmitic, alpha-linolenic, and oleic acids) that could have been responsible for the antimicrobial activity were identified in the extracts. beta-Cyclocitral, alpha- and beta-ionone, neophytadiene, and phytol were identified among other volatile compounds; all of these compounds have previously been described as antimicrobial agents.     

Soldering a gas diffusion layer to a stainless steel bipolar plate using metallic tin

A novel investigation to decrease the interfacial contact resistance of stainless steel bipolar plates was performed. A thin layer of Sn was electrodeposited onto a bipolar plate and subsequently joined with a gas diffusion layer through hot-pressing at a temperature around the melting point of tin. This procedure was optimised, depositing 30 μm of Sn onto the stainless steel bipolar plate before hot-pressing at 230 °C and 0.5 bar for 20 min. A contact resistance of 5.45 mΩ cm² at 140 N cm^?2 was obtained, with low values maintained after exposure to both in-situ and ex-situ conditions. The in-situ testing in a fuel cell produced excellent results, with minor increases in contact resistance from 8.8 to 9.2 mΩ cm² and decreases in cell voltage from 0.714 to 0.667 V after 200 h of operation. These values are comparable to gold plated stainless steel, showing that combining a gas diffusion layer with electrodeposited Sn through hot-pressing is a promising low-cost coating for bipolar plates in PEM fuel cells.     

Minor Constituents in Canola Oil Processed by Traditional and Minimal Refining Methods

The minimal refining method described in the present study made it possible to neutralize crude canola oil with Ca(OH)₂, MgO, and Na₂SiO₃ as alternatives to NaOH. After citric acid degumming, about 98 % of the phosphorous content was removed from crude oil. The free fatty acid content after minimal neutralization with Ca(OH)₂ decreased from 0.50 to 0.03 %. Other quality parameters, such as peroxide value, anisidine value, and chlorophyll content, after traditional and minimal neutralization were within industrial acceptable levels. The use of Trisyl silica and Magnesol R60 made it feasible to remove the hot-water washing step and decreased the amount of residual soap to <10 mg/kg oil. There were no significant changes in chemical characteristics of canola oil after using wet and dry bleaching methods. During traditional neutralization, the total tocopherol loss was 19.6 %, while minimal refining with Ca(OH)₂, MgO, and Na₂SiO₃ resulted in 7.0, 2.6, and 0.9 % reductions in total tocopherols. Traditional refining removed 23.6 % of total free sterols, while after minimal refining free sterols content did not change. Both traditional and minimal refining resulted in almost complete removal of polyphenols from canola oil. Total phytosterols and tocopherols in two cold-pressed canola oils were 774 and 836 mg/100 g, and 366 and 354 mg/kg, respectively. The minimal refining method described in the present study was a new practical approach to remove undesirable components from crude canola oil meeting commercial refining standards while preserving more healthy minor components.     

Disruption of O-Linked N-Acetylglucosamine Signaling in Placenta Induces Insulin Sensitivity in Female Offspring

Placental dysfunction can lead to fetal growth restriction which is associated with perinatal morbidity and mortality. Fetal growth restriction increases the risk of obesity and diabetes later in life. Placental O-GlcNAc transferase (OGT) has been identified as a marker and a mediator of placental insufficiency in the setting of prenatal stress, however, its role in the fetal programming of metabolism and glucose homeostasis remains unknown. We aim to determine the long-term metabolic outcomes of offspring with a reduction in placental OGT. Mice with a partial reduction and a full knockout of placenta-specific OGT were generated utilizing the Cre-Lox system. Glucose homeostasis and metabolic parameters were assessed on a normal chow and a high-fat diet in both male and female adult offspring. A reduction in placental OGT did not demonstrate differences in the metabolic parameters or glucose homeostasis compared to the controls on a standard chow. The high-fat diet provided a metabolic challenge that revealed a decrease in body weight gain (p = 0.02) and an improved insulin tolerance (p = 0.03) for offspring with a partially reduced placental OGT but not when OGT was fully knocked out. Changes in body weight were not associated with changes in energy homeostasis. Offspring with a partial reduction in placental OGT demonstrated increased hepatic Akt phosphorylation in response to insulin treatment (p = 0.02). A partial reduction in placental OGT was protective from weight gain and insulin intolerance when faced with the metabolic challenge of a high-fat diet. This appears to be, in part, due to increased hepatic insulin signaling. The findings of this study contribute to the greater understanding of fetal metabolic programming and the effect of placental OGT on peripheral insulin sensitivity and provides a target for future investigation and clinical applications.     

Mineral composition of the red and green pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis>) from Tenerife Island

The content of macroelements (Na, K, Ca, Mg and P) and microelements (Fe, Cu, Zn, Mn and B) in green and red pepper samples consumed on the island of Tenerife, Canary Islands, has been determined. Analysis has shown the influence of the ripening stage on the mineral content of the pepper. Red pepper presents higher K, Mg, P, Fe, Cu, Zn, Mn and B concentration levels than green pepper. There are differences between the values obtained in this study and the values shown in different food composition tables; our results are higher in Na, Ca and Mg, and lower in K and Fe.     

正癸烷+正戊醇,+1-己醇,+庚醇二元混合物在293.15到363.15K和大气压力下的密度和粘度（英文）

Densities (ρ) and dynamic viscosities (η) for three binary mixtures of n-decane with 1-pentanol, 1-hexanol and 1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire composition range. The density and viscosity are measured using a vibrating tube densimeter and a cylindrical Couette type rotating viscometer, respectively. Excess molar volumes (VE), viscosity deviations (Δη) and excess Gibbs energy of activation of viscous flow (ΔG*E) are calculated from the experimental measurements. Intermo-lecular and structural interactions are indicated by the sign and magnitude of these properties. Partial molar vol-umes and infinity dilution molar partial volumes are also calculated for each binary system. These results are correlated using Redlich–Kister type equations.     

Association between Serum Soluble CD154 Levels and Mortality in Patients with Malignant Middle Cerebral Artery Infarction

Background: CD154 and its soluble counterpart (sCD154) are proteins of the tumor necrosis factor (TNF) family and exhibit proinflamatory and procoagulant properties. Higher circulating sCD154 levels have been found in ischemic stroke patients than in controls. However, the association between circulating sCD154 levels and mortality in ischemic stroke patients has not been reported, and was the focus of this study. Methods: This was a multicenter, observational and prospective study carried out in six Spanish Intensive Care Units. We measured serum sCD154 from 50 patients with severe malignant middle cerebral artery infarction (MMCAI), defined as Glasgow Coma Scale (GCS) lower than 9, at the moment of the severe MMCAI diagnosis and from 50 healthy controls. The end-point of the study was 30-day mortality. Results: We found higher serum sCD154 levels in patients with severe MMCAI than in healthy controls (p < 0.001). We found higher serum sCD154 levels (p < 0.001) in non-surviving (n = 26) than in surviving MMCAI patients (n = 24). Multiple binomial logistic regression analysis showed that serum sCD154 levels >1.41 ng/mmL were associated with 30-day mortality (OR = 10.25; 95% CI = 2.34–44.95; p = 0.002). Conclusions: The new more important finding of our study was that serum sCD154 levels in MMCAI patients were associated with mortality.     

Plug-in bandwidth selection in kernel hazard estimation from dependent data

The plug-in bandwidth selection method in nonparametric kernel hazard estimation is considered, and a weak dependence on the sample data is assumed. A general result of asymptotic optimality for the plug-in bandwidth is presented, that is valid for the hazard function, as well as for the density and distribution functions. In a simulation study, this method is compared with the “leave more than one out” cross-validation criterion under dependence. Simulations show that smaller errors and much less sample variability can be reached, and that a good selection of the pilot bandwidth can be done by means of “leave one out” cross-validation. Finally, an application to an earthquake data set is made.