Impact of cycling temperatures on Fusarium verticillioides and Fusarium graminearum growth and mycotoxins production in soybean

BACKGROUND: Fusarium graminearum and F. verticillioides are two very important mycotoxigenic species as they cause diverse diseases in crops. The effects of constant and cycling temperatures on growth and mycotoxin production of these species were studied on soybean based medium and on irradiated soya beans. RESULTS: F. graminearum grew better when was incubated at 15, 20 and 15–20 °C (isothermal or cycling temperature) during 21 days of incubation. Maximum levels of zearalenone and deoxynivalenol (39.25 and 1040.4 µg g^?1, respectively) were detected on soya beans after 15 days of incubation and the optimal temperature for mycotoxin production was 15 °C for zearalenone and 20 °C for deoxynivalenol. F. verticillioides grew better at 25 °C in culture medium and at 15/20 °C and 15/25 °C on soybean seeds. Fumonisin B₁ was produced only in culture medium, and the maximum level (7.38 µg g^?1) was found at 15 °C after 7 days of incubation. CONCLUSION: When growth and mycotoxin production under cycling temperatures were predicted from the results under constant conditions, observed values were different from calculated for both species and substrate medium. Therefore, care should be taken if data at constant temperature conditions are to be extrapolated to real field conditions. Copyright © 2012 Society of Chemical Industry     

Ultrastructural morphometric study of the prostate of the rat after microsurgical denervation

In an epidemiological study, markers of bone formation (serum osteocalcin and C-terminal propeptide of type I collagen) and bone resorption [urinary type I collagen peptides (Crosslaps), urinary total pyridinoline (TPYRI), urinary deoxypyridinoline (DPYRI) as well as female sex hormones (serum estradiol)], follicle-stimulating hormone (FSH) and luteinizing hormone were measured in 237 women. This cohort aged 44-66 years, came for their first medical examination since menopause to the outpatient menopause clinic at the Kaiser-Franz-Josef-Hospital, Vienna. The women were all 0.5-5.0 years since cessation of menses and were not taking medications other than hormone replacement therapy [52 cases, 21.9%)] and had no diseases known to affect bone and mineral metabolism. The best correlation was found between urinary DPYRI and urinary TPYRI (r = 0. 63, P = 0.0001), followed by urinary Crosslaps and urinary DPYRI (r = 0.47, p = 0.0001). Only weak but significant correlations between E2 and urinary Crosslaps (r = -0.21, P < 0.0001) as well as serum E2 and serum osteocalcin (r = -0.16, P = 0.0007), were observed. Of the 237 women 53% suffered from a severe E2 deficiency (E2 < 10.0 ng/liter). In these patients, urinary Crosslaps (+48%) and serum osteocalcin (+22%) were significantly higher (P < 0.0001) compared with those patients with E2 levels > 10 ng/liter. Women with E2 levels >10 ng/liter were further subdivided into those with and without sex hormone replacement therapy, whereby no statistical differences in any of the biochemical markers could be observed between these groups. We could clearly demonstrate that in postmenopausal women suffering from severe E2 deficiency (E2 < 10 ng/liter), urinary Crosslaps and serum osteocalcin are significantly increased, indicating in principle a clear correlation between E2 deficiency and these markers of bone turnover.     

Comparative analysis of a DI diesel engine fuelled with biodiesel blends during the European MVEG-A cycle: Preliminary study (I)

The present work consists of introducing the tests and facilities used to perform a comparative analysis of a diesel engine working with different blends of biodiesel fuel during the New European Driving Cycle. Furthermore, as a preliminary study, it was interesting to know the effects of biodiesel fuel on a common-rail high pressure injection system, those more useful in modern light duty diesel engines, as a consequence of its different physicochemical properties compared with conventional diesel fuel. As the real goal of the study is to compare fairly performance and emissions from the engine, it was essential to know any injection effects owed to fuel's own characteristics that finally would affect those parameters that will be evaluated.A complete fuel characterization for diesel and biodiesel fuels, as the EN 590 and the EN 14214 standard specifications, was performed in order to quantify the differences between both fuels. A priori, it could be thought that viscosity and density values will be the most significant parameters capable of altering the injection rate. As positive results, it was obtained that the common-rail high pressure injection system was totally blind in the injection rate measurements, even the significant differences between both fuels, taking into account the counterbalancing effects generated by two parameters mentioned before.The second part of the study deals with engine performance and pollutant emissions on an unmodified common-rail turbocharged diesel engine running with biodiesel fuel blends during the New European Driving Cycle.     

Comparative analysis of a DI diesel engine fuelled with biodiesel blends during the European MVEG-A cycle: Performance and emissions (II)

The use of biodiesel is under evaluation as a possible fuel alternative to fossil fuels. Despite the literature available concerning the effect of biodiesel on engine performance and emissions under steady operation, there are not many research studies which cope with the effect of biodiesel during transient operation. Moreover, it is interesting to study the repercussions that the use of biodiesel has on complete vehicle performance and emissions. In this sense, the part 1 of the present paper deals with a preliminary analysis where the test facilities and procedures are explained, and the effects of the physicochemical properties of biodiesel on fuel injection are studied. To cope with the repercussion of the use of biodiesel in engine emissions during the MVEG-A cycle in this part of the paper a deep analysis of the pollutant emissions obtained during tests is done. Based on this analysis the paper also presents an approach to improve the engine control calibration to take advantage of utilising biodiesel.     

PLGA based drug delivery systems (DDS) for the sustained release of insulin: insight into the protein/polyester interactions and the insulin release behavior

BACKGROUND: Drug delivery systems (DDS) were designed using insulin as model drug and poly (lactic–co‐glycolic) copolymers (PLGA) as polymeric matrix. The carriers were synthesized by direct self‐assembly of the insulin and the polyester under mild conditions. RESULTS: The kind and level of association between the protein and the polymer were studied using computational methods (combined MM2/PM3) and spectroscopic tools (Fourier transform infrared (FTIR), energy dispersive X‐ray (EDX) and X‐ray fluorescence spectroscopy (XFS)). The effect of the number average molecular weight (M_n) of the copolymer on the association efficiency (AE) drug–polymer as well as on the release profile has been explored. Mathematical models were used to predict the insulin release kinetic and mechanism. CONCLUSIONS: Satisfactory protein/PLGA association efficiencies (between 77 and 99%) were registered depending on the M_n of the PLGA. Hydrophobic and hydrophilic interactions were detected between the protein and the polymeric network by computational analysis. In vitro release studies demonstrated that copolyesters of about 8600 and 1500 Da were suitable for the gradual release of insulin while PLGA oligomers of average molecular weight between 700 and 800 Da were unsuitable as DDS. The insulin release kinetics fits well with the Korsmeyer model, following the anomalous transport mechanism. Copyright © 2010 Society of Chemical Industry     

FVF‐Based Low‐Dropout Voltage Regulator with Fast Charging/Discharging Paths for Fast Line and Load Regulation

A new internally compensated low drop‐out voltage regulator based on the cascoded flipped voltage follower is presented in this paper. Adaptive biasing current and fast charging/discharging paths have been added to rapidly charge and discharge the parasitic capacitance of the pass transistor gate, thus improving the transient response. The proposed regulator was designed with standard 65‐nm CMOS technology. Measurements show load and line regulations of 433.80 μV/mA and 5.61 mV/V, respectively. Furthermore, the output voltage spikes are kept under 76 mV for 0.1 mA to 100 mA load variations and 0.9 V to 1.2 V line variations with rise and fall times of 1 μs. The total current consumption is 17.88 μA (for a 0.9 V supply voltage).     

Accessibility of university websites worldwide: a systematic literature review

Universal Access in the Information Society - The identity and institutional image of universities are presented to the world through their websites. On their websites, universities publish their...     

Mould growth and mycotoxin production as affected by Equisetum arvense and Stevia rebaudiana extracts

Cereals are very important for human and animal diet. However, agricultural products can be contaminated by moulds and their mycotoxins. On the other hand, natural plant products with antimicrobial properties could be a possibility to control mycotoxigenic fungi in foods and feeds. In this study, Equisetum arvense and Stevia rebaudiana extracts were tested for their efficacy against a range of mycotoxigenic fungi. Maize agar medium (MAM 2%) was used for this study and E. arvense and S. rebaudiana extracts were added at different concentrations (1–3%) under different water activity (a_w) levels (0.85–0.95). Six mycotoxigenic moulds were inoculated and incubated at different temperatures (15–30 °C) during 21 days. In general, no growth was observed with E. arvense extract at 3% in all studied conditions for all isolates. However, with S. rebaudiana extract at 2–3%, growth was not significantly decreased (p < 0.05) in most of the cases. Finally, in terms of toxin production, results were not conclusive. The use of E. arvense extracts as antifungals and antimycotoxigenics and their application should be further explored.