Mass spectrometric determination of 234U/238U ratio with improved precision

A new mass spectrometric method is proposed for measurement of 234U/238U ratio with a single Daly electron multiplier detector using the general peak jump method. The method is based on precise measurement of the 235U/238U ratio and 234U/235U ratio, which are used to calculate the 234U/238U ratio using the equation 234U/238U = 235U/238U x 234U/235U. The results show a significant improvement, i.e., more than 35 times better precision in measuring the (234)U/(238)U ratio with this method (sigma = 2.9 x 10(-8)) as compared to direct measurement of 234U/238U (sigma = 1.1 x 10(-6)). The method widens the applicability of the single collector system, and it will potentially be helpful to improve the precision in the case of the static multicollector system also.     

CLA Has a Useful Effect on Bone Markers in Patients with Rheumatoid Arthritis

Rheumatoid arthritis is a systemic, chronic disease which may increase the risk of osteoporosis. This study was carried out in order to examine the effect of conjugated linoleic acid (CLA) on bone markers in rheumatoid arthritis disease which is the most common autoimmune disease. The present study is a randomized double‐blind clinical trial. Subjects included 52 patients with active rheumatoid arthritis who were divided into two groups. Group I received standard treatment plus 2 daily 1.25 g capsules (Containing about 2 g of 9‐cis 11‐trans isomer and 10‐cis 12‐trans isomer in ratio of 50 ?50 CLA in glycerinated form), Group II received standard treatment plus 2 Placebo 1.25 g capsules containing sunflower oil with high oleic acid. Telopeptides C, osteocalcin, and MMP3 were analyzed by ELISA method, PGE₂ was done by competitive enzymatic immunoassay method, and IGF‐1 was analyzed by the IRMA method based on the sandwich method and ALK‐P of bone. Before and after the intervention, the questionnaires about general information, nutrition assessment and medical history were filled out by the subjects. Nutritional assessment was done by a 24‐h record questionnaire for the three‐day diet. The results were analyzed using SPSS software (version 18). Findings: There was no significant difference between the groups in enzyme activity of ALK‐P of bone, PGE₂ and MMP3 variables. However, differences between the two groups in terms of activity of telopeptides C, Osteocalcin, and IGF1 were significant (P < 0.05). CLA has a potentially beneficial effect on bone markers in patients with rheumatoid arthritis. Therefore, in order to study the effect of CLA on bone health in patients with RA and all patients with autoimmune and bone diseases more studies with longer duration and evaluation of bone mass density are required.     

Detoxification of cyanide by immobilised fungi

Cyanide detoxification was studied by immobilisation of fungal mycelia that had been induced to form cyanide hydratase (formamide hydrolyase) which is able to hydrolyse cyanide to formamide. The fungal pathogens of cyanogenic plants, Stemphylium loti, Gloeocercospora sorghi and Fusarium moniliforme were immobilised using polyelectrolyte flocculating agents. The effect of immobilisation on the enzymic properties of S. loti and G. sorghi were investigated. The apparent K_m values increased from 21.0 mmol and 25.5 mmol KCN to 43.5 mmol and 71.0 mmol KCN, respectively. The pH profile for the two enzymes widened on immobilisation. The stoichiometry of 1:1 cyanide utilisation to formamide formation was retained on immobilisation, with complete conversion of 70 mmol KCN in 120 min by 0.12 g dry wt of S. loti and in 6 min by 0.13 g dry wt of G. sorghi. When the two fungi were stabilised by immobilisation, and tested in column reactors containing 1.2 g dry wt of S. loti and 1.3 g dry wt of G. sorghi, they completely converted cyanide (70 mmol; added continuously at 7.5 ml h^?1) into formamide for 2 days and 30 days, respectively. Stability was enhanced by inclusion of 1.0 mmol glucose in the 70 mmol KCN solution, by a further 10 h for S. loti and an extra 10 days for G. sorghi. Operational stabilities of immobilised G. sorghi (1.3 g dry wt) and F. moniliforme (1.0 g wet wt) in column reactors, with 100 % cyanide conversion, at varying flow rates was investigated. G. sorghi was stable for 15, 10 and 2 days whereas F. moniliforme was only stable for 48, 20 and 10 h at 30, 60 and 120 ml h^?1 flow rates respectively.     

Monitoring and maintaining the water clarity of salinity gradient solar ponds

A common problem encountered in salinity-gradient solar ponds is the growth of various types of algae and bacterial populations, which affects the brine clarity and hence reduces thermal performance. Algae and bacterial populations are enhanced by the presence of organic nutrient such as nitrogen and phosphorus. A comprehensive study was undertaken on three salinity-gradient solar ponds in Australia: a 3000 m² sodium chloride solar pond at Pyramid Hill in Northern Victoria; a 50 m² sodium chloride; and 15 m² magnesium chloride solar pond at RMIT University in Bundoora, Victoria. The experimental study involved monitoring the clarity of these three ponds and testing chemical and biological treatment methods to see their effect on the brine transparency. The sources of turbidity and their impacts on clarity and efficiency of salinity-gradient solar ponds are presented in detail in this paper. The initial observation showed that the amount of sunlight is reduced due to the heavy algal growth creating instability in the solar pond as it absorbs light. Two treatment methods were applied to these solar ponds and experiments were conducted to study the turbidity reduction in the solar ponds. In the RMIT magnesium chloride solar pond, diluted hydrochloric acid was injected in the pond to reduce the pH and turbidity levels. Algal blooms were observed and found in the pond where the pH was between 5.5 and 8. It was observed from the experimental study that pH values should be kept below 4.5 to maintain low turbidity and prevent algae growth. The introduction of brine shrimps was also found to be very effective and economical to control algae, provided the oxygen has not depleted due to advanced heavy algal growth. The investigation concluded that hydrochloric acid could be used initially as a shock treatment to kill all the algae and then brine shrimps could be introduced to control the growth of algal and maintain transparency. This analysis showed that by using a combination of chemical and biological treatment methods, the pond clarity can be maintained and the thermal efficiency of the solar pond can be improved.     

Targeting microbial biofilms: by Arctium lappa l. synthesised biocompatible CeO2 ‐NPs encapsulated in nano‐chitosan

This study is planned to synthesise new biocompatible, nano antimicrobial formulation against biofilm producing strains. Aqueous root extract of Arctium lappa l. was used to synthesise ceria nanoparticles (CeO₂ ‐NPs). The synthesised nanoparticles were encapsulated with nano‐chitosan by sol–gel method and characterised using standard techniques. Gas chromatography‐mass spectrometer of Arctium lappa l. revealed the presence of ethanol, acetone, 1‐ propanol, 2‐methylethane, 1,1‐di‐ethoxy, 1‐Butanol, and oleic acid acted as reducing and surface stabilising agents for tailoring morphology of CeO₂ ‐NPs. Erythrocyte integrity after treatment with synthesised nanomaterials was evaluated by spectrophotometer measurement of haemoglobin release having biocompatibility. Scanning electron microscopy revealed the formation of mono dispersed beads shaped particles with mean particle size of 26.2 nm. X‐ray diffractometry revealed cubic crystalline structure having size of 28.0 nm. After encapsulation by nano‐chitosan, the size of CeO₂ ‐NPs enhances to 48.8 nm making average coverage of about 22.6 nm. The synthesised nanomaterials were found effective to disrupt biofilm of S. aureus and P. aeruginosa. Interestingly, encapsulated CeO₂ ‐NPs revealed powerful antibacterial and biofilm disruption activity examined by fluorescent live/dead staining using confocal laser scanning microscopy. The superior antibacterial activities exposed by encapsulated CeO₂ ‐NPs lead to the conclusion that they could be useful for controlling biofilm producing multidrug resistance pathogens.Inspec keywords: particle size, microorganisms, organic compounds, nanomedicine, sol‐gel processing, cellular biophysics, scanning electron microscopy, optical microscopy, nanoparticles, antibacterial activity, fluorescence, biomedical materials, nanofabrication, X‐ray diffraction, chromatography, filled polymers, cerium compoundsOther keywords: microbial biofilms, aqueous root extract, sol–gel method, gas chromatography‐mass spectrometer, 1‐di‐ethoxy, 1‐Butanol, nanomaterial synthesis, mean particle size, antibacterial activities, ethanol, acetone, 1‐ propanol, biocompatible ceria‐nanoparticle encapsulation, nano‐chitosan, Arctium lappa l., oleic acid, erythrocyte integrity, spectrophotometer measurement, haemoglobin release, mono dispersed beads shaped particle formation, X‐ray diffractometry, cubic crystalline structure, fluorescent live/dead staining, confocal laser scanning microscopy, multidrug resistance pathogens, size 26.2 nm, size 28.0 nm, size 48.8 nm, size 22.6 nm, CeO₂      

Effect of fibers treatment on dynamic mechanical and thermal properties of epoxy hybrid composites

Epoxy hybrid composites fabricated by reinforcing 2‐hydroxy ethyl acrylate (2‐HEA) treated oil palm empty fruit bunch (EFB) and jute fibers. It assume that chemical modification of jute and oil palm EFB fibers increased fiber/matrix interfacial bonding and it results in enhanced thermal properties of hybrid composites. Dynamic mechanical and thermal analysis of treated hybrid composites was carried out. Results indicated that chemical modification of oil palm EFB and jute fibers affect the dynamic mechanical and thermal properties of hybrid composites. The storage modulus values of hybrid composites increases with chemical treatment and loss modulus increased with fiber treatment in hybrid composites. Damping factor peak values of treated hybrid composites shifted toward the lower temperature compared to both untreated hybrid composites. Cole–Cole analysis was made to understand the phase behaviour of the hybrid composites. Thermogravimetric analysis indicated an increased in thermal stability of hybrid composite with the incorporation of chemically modified fibers. POLYM. COMPOS., 36:1669–1674, 2015. © 2014 Society of Plastics Engineers     

Hydrogen adsorption properties of carbide-derived carbons at ambient temperature and high pressure

Properties of the adsorbed hydrogen phase have been studied for hydrogen adsorption in three carbide derived carbons: SiC-CDC, steam/CO₂ activated SiC-CDC and TiC-CDC. Using the excess hydrogen uptake isotherm at hydrogen pressures above 120 MPa where adsorption has finished, the adsorbate volume has been determined and the adsorbate density has been calculated at ambient temperatures. Absolute adsorption isotherms have been constructed by assuming the adsorbate volume is equivalent to the pore volume and is therefore constant. This study indicates that all three CDCs had the same maximum adsorbate density, with the adsorption proportional to the total pore volume.     

Saponin-Based Nanoemulsification Improves the Antioxidant Properties of Vitamin A and E in AML-12 Cells

Our work aimed to investigate the protective effects of saponin-based nanoemulsions of vitamin A and E against oxidative stress-induced cellular damage in AML-12 cells. Saponin nanoemulsions of vitamin A (SAN) and vitamin E (SEN) were prepared by high-pressure homogenization and characterized in terms of size, zeta potential, and polydispersity index. SEN and SAN protect AML-12 cells against oxidative stress-induced cellular damage more efficiently via scavenging reactive oxygen species (ROS), and reducing DNA damage, protein carbonylation, and lipid peroxidation. These results provide valuable information for the development of nanoemulsion-based delivery systems that would improve the antioxidant properties of vitamin A and E.     

Antibacterial activity and cholesterol assimilation of lactic acid bacteria isolated from traditional Iranian dairy products

In this study, lactic acid bacteria were isolated from ewe milk, traditional yoghurt and sour buttermilk samples collected from different areas of Azarbayjan-e-sharqi in Iran. All the isolates were screened for their ability to produce bacteriocin like inhibitory substances (BLIS) by studying their inhibitory action against pathogens like Listeria monocytogenes, Salmonella enteritidis and Staphylococcus aureus, after eliminating the effect of organic acids and hydrogen peroxide. According to results, four of the isolates identified as Lactobacillus brevis, Lactobacillus pentosus, Pedoicoccus acidilactici and Lactobacillus paracasei were unaffected by the action of pH neutralization and hydrogen peroxide and showed inhibitory action against the tested pathogens. The inhibitory activities demonstrated by these isolates were completely inhibited in the presence of proteolytic enzymes.