Idle time in the washing and iron concentration in leachate removed: two basic parameters in the desulphurization of coal in a packed column

Column biodesulphurization of coal is at the experimental stage and is influenced by many variables including temperature, pH, particle size, concentration of iron in solution, among others. Idle time in the washing process and the concentration of dissolved iron in the purged leachate are two variables with a definite effect on the yield of the desulphurization system. In the laboratory, several trials were run with columns packed with coal for different idle times: 1, 2, 3, 5, 6 and 7 days, and for different concentrations of iron in the purged leachate: 500 to 4,000 mg/l. The optimal values for the two variables; that is, those allowing for the highest desulphurization yields, were idle times of 3 and 5 days, which give an elimination of 56% and 49% of pyritic sulphur, respectively, and 3,000 mg/l of iron concentration in the purged leachate, giving a decrease in pyritic sulphur in coal of 57%.     

Vaginal bacterial microflora modifications during the growth of healthy cows

The aim of this work was first, to determine the predominant groups capable of colonizing the vagina and maintaining high numbers with time. The normal microbial flora of the cow's vagina and its evolution from weaning to service was then studied using standard microbiological methods. The results show that the most dominant bacteria belong to the streptococci, followed by the staphylococci, with similar levels during the whole study period. Enterobacteriaceae and lactobacilli were present at very low levels, the latter increasing during the cow's growth, suggesting some kind of hormonal influence. The results will allow the selection of micro-organisms with probiotic characteristics, classified as GRAS (Generally Regarded as Safe), to be used in the prevention of infections in the vaginal tract of cows, such as metritis, which produces delayed periods between partum and conception, and consequent economic losses.     

High-pressure shift freezing. Part 1. Amount of ice instantaneously formed in the process

A mathematical model to calculate the amount of ice formed instantaneously after a rapid expansion in high-pressure shift processes (HPSF) was developed. It considers that when water is expanded it does not extend over its melting curve but reaches a metastable state (supercooled water), which also occurs in practice. Theoretical results appear to agree with experimental data.     

Enzymatic synthesis of lactic acid derivatives with emulsifying properties

Novozym 435 (50 g l^–1) catalyzed the synthesis of n-octyl--d-glucopyranoside lactate by transesterification between n-octyl--d-glucopyranoside (30 g l^–1) and ethyl lactate (100 g l^–1) in acetone. In 12 h, a molar yield of 87% n-octyl -d-glucopiranoside lactate was obtained at a overall conversion of 90%.     

Quantitative enzymatic production of 6-O-acylglucose esters

Selective production of emulsifiers from glucose and fatty acids has been achieved using an immobilized Candida antarctica lipase. Optimization of process selectivity considers the solubilities of the sugar and its monoesters in acetone at different temperatures, the percentage of this organic solvent in the reaction mixture, and the reaction temperature. The solvent (acetone) is both easily eliminated and accepted by the European Community for use in the manufacture of foods and/or food additives. Different fatty acids with a longer length chain than that of caprylic acid may be employed. For saturated fatty acids longer than lauric acid, continuous precipitation of the monoester as it is formed at 40 degrees C permits nearly complete conversion (98%) of glucose to the monoester within 2-3 days. The procedure does not require total dissolution of the sugar, and precipitation of the monoester permits selective conversion of charges of glucose higher than 100 mg/mL solvent. A scaleup of the process under the optimum conditions gives high yields of 6-O-lauroyl glucose, which may be readily prepared on a gram scale. Copyright 1998 John Wiley & Sons, Inc.     

Induction of astaxanthin accumulation by nitrogen and magnesium deficiencies in Haematococcus pluvialis

Haematococcus pluvialis was cultured under N– and Mg+2-deficient conditions with two light intensities: 40 and 230 mol m² s–1. Highest astaxanthin concentration, 49.5 g·ml–1, was obtained when high light was applied under N-deficient conditions. N-deficiency has a greater effect than high light intensity on astaxanthin synthesis by exerting a stronger blocking effect on cell division. The effect of high light was synergetic with the other stress conditions in stimulating the synthesis of astaxanthin. Mg+2 deficiency also stimulated the synthesis of astaxanthin but produced lower concentrations: 7 and 26 g·ml–1 for low and high light intensities respectively. When both N and Mg+2 were absent from the culture media the concentration of astaxanthin was lower than with N-deficiency alone but higher than with Mg+2-deficiency. © Rapid Science Ltd. 1998     

Immunomodulator-Based Enhancement of Anti Smallpox Immune Responses

Background

The current live vaccinia virus vaccine used in the prevention of smallpox is contraindicated for millions of immune-compromised individuals. Although vaccination with the current smallpox vaccine produces protective immunity, it might result in mild to serious health complications for some vaccinees. Thus, there is a critical need for the production of a safe virus-free vaccine against smallpox that is available to everyone. For that reason, we investigated the impact of imiquimod and resiquimod (Toll-like receptors agonists), and the codon-usage optimization of the vaccinia virus A27L gene in the enhancement of the immune response, with intent of producing a safe, virus-free DNA vaccine coding for the A27 vaccinia virus protein.

Methods

We analyzed the cellular-immune response by measuring the IFN-γ production of splenocytes by ELISPOT, the humoral-immune responses measuring total IgG and IgG2a/IgG1 ratios by ELISA, and the TH1 and TH2 cytokine profiles by ELISA, in mice immunized with our vaccine formulation.

Results

The proposed vaccine formulation enhanced the A27L vaccine-mediated production of IFN-γ on mouse spleens, and increased the humoral immunity with a TH1-biased response. Also, our vaccine induced a TH1 cytokine milieu, which is important against viral infections.

Conclusion

These results support the efforts to find a new mechanism to enhance an immune response against smallpox, through the implementation of a safe, virus-free DNA vaccination platform.     

Life and death of a BiP substrate

BiP is the mammalian endoplasmic reticulum (ER) Hsp70 orthologue that plays a major role in all functions of this organelle including the seemingly opposing functions of aiding the maturation of unfolded nascent proteins and identifying and targeting chronically unfolded proteins for degradation. The recent identification of mammalian BiP co-factors combined with delineation of the ER degradation machinery and data suggesting that the ER is subdivided into unique regions helps explain how these different functions can occur in the same organelle and raises some unresolved issues.     

Phosphatidylinositol 3-kinase, MEK-1 and p38 mediate leptin/interferon-gamma synergistic NOS type II induction in chondrocytes

In a previous study, we established that leptin acts synergistically with interferon-gamma in inducing nitric oxide synthase type II in cultured chondrocytes via Janus kinase-2 activation. However, the exact molecular mechanism that accounts for this synergism is not completely understood. The aim of the present study was to further delineate the signalling pathway used by leptin/interferon-gamma in the nitric oxide synthase type II induction in chondrocytes. Consequently, the roles of PI-3 kinase, MEK1 and p38 kinase were investigated using specific pharmacological inhibitors (Wortmannin, LY 294002, PD 098,059 and SB 203580). For this purpose, the amount of stable nitrite, the end product of NO generation by activated chondrocytes, has been evaluated by Griess colorimetric reaction in culture medium of human primary chondrocytes and in the murine ATDC5 cell line stimulated with leptin (400 nM) and interferon-gamma (1 ng/ml), alone or in combination. Specific inhibitors for PI-3K, MEK1 and p38 were added 1 h before stimulation. Nitric oxide synthase type II mRNA was investigated by real-time RT-PCR and NOS type II protein expression has been evaluated by western blot analysis. Our results showed that, as expected, leptin synergizes with IFN-gamma in inducing NO accumulation in the supernatant of co-stimulated cells. Pre-treatment with Wortmannin, LY 294002, PD 098,059 and SB 203580 caused a significant decrease in nitrite production, NOS type II protein expression and NOS type II mRNA expression induced by leptin and interferon-gamma co-stimulation. These findings were confirmed in 15 and 21-day differentiated ATDC5 cells, and in normal human primary chondrocytes. This is the first report showing that NOS type II induction triggered by co-stimulation with leptin and interferon-gamma is mediated by a signaling pathway involving PI-3K, MEK1 and p38.