66 research outputs found
Assessing coronary heart disease in women
No full textCoronary heart disease (CHD) is a leading cause of mortality in women worldwide. However CHD is still considered to be a male disease and it is likely to be under-diagnosed in women since symptoms are different in women and diagnostic tests may be less specific or sensitive. This review examines the symptoms and risk factors for CHD in women. The role of invasive and non-invasive tests together with their prognostic implications as well as indications for coronary revascularization will be discussed. New research should focus on the role of gender differences in CHD and trials specifically designed to study wome
Mild pretreatments to increase fructose consumption in saccharomyces cerevisiae wine yeast strains
No full textThe present research investigates the effect of different pretreatments on glucose and fructose consumption and ethanol production by four Saccharomyces cerevisiae wine strains, three isolated and identified from different wine regions in Turkey and one reference strain. A mild stress temperature (45 °C, 1 h) and the presence of ethanol (14% v/v) were selected as pretreatments applied to cell cultures prior to the fermentation step in synthetic must. The goodness fit of the mathematical models was estimated: linear, exponential decay function and sigmoidal model were evaluated with the model parameters R2 (regression coefficient), RMSE (root mean square error), MBE (mean bias error) and χ2 (reduced Chi-square). Sigmoidal function was determined as the most suitable model with the highest R2 and lower RMSE values. Temperature pretreatment allowed for an increase in fructose consumption rate by two strains, evidenced by a t90 value 10% lower than the control. One of the indigenous strains showed particular promise for mild temperature treatment (45 °C, 1 h) prior to the fermentation step to reduce residual glucose and fructose in wine. The described procedure may be effective for indigenous yeasts in preventing undesirable sweetness in wines
Acetic acid bacteria as enantioselective biocatalysts
No full textAcetic acid bacteria (five strains of Acetobacter and five strains of Gluconobacter) were used for the biotransformation of different primary alcohols (2-chloropropanol and 2-phenylpropanol) and diols (1,3-butandiol, 1,4-nonandiol and 2,3-butandiol). Most of the tested strains efficiently oxidized the substrates. 2-Chloropropanol and 1,3-butandiol were oxidized with good rates and low enantioselectivity (enantiomeric excess = 18–46% of the S-acid), while microbial oxidation of 2-phenylpropanol furnished (S)-2-phenyl-1-propionic acid with enantiomeric excess (e.e.) >90% with 10 strains. The dehydrogenation of 2,3-butandiol was strongly dependent on the stereochemistry of the substrate; the meso form gave S-acetoin with all the tested strains, the only exception being a Gluconobacter strain. The formation of diacetyl was observed only by using R,R-2,3-butandiol with Acetobacter strains. Oxidation of 1,4-nonandiol gave -nonanoic lactone in one step, although with moderate enantioselectivity
Intra-procedural continuous venous venous hemofiltration in preventing contrast induced nephropathy in patients with very low creatinine clearance undergoing coronary intervention
No full textIntra-procedural continuous venous venous hemofiltration in preventing contrast induced nephropathy in patients with very low creatinine clearance undergoing coronary interventio
Alkaline pretreatment of sorghum and wheat straw for increasing methane production
No full textThe aim of this study was to determine the effect of alkaline pretreatment on fiber composition,biodegradability and methane production rate of sorghum forage and wheat straw. Samples were treated at 40 °C for 24 h with a sodium hydroxide solution. The specific dosages were 1, 3 and 10gNaOH/100gTS. By increasing the alkaline dosage, a reduction in the total fiber content and an increase in COD solubilization is observed. Total sugars content increased up to five times at the highest alkaline dosage with respect to control samples, proving that alkali pretreatment improves substrate swelling and hydrolysis of hemicellulose.
Biochemical methane production tests showed that the chemical pretreatment increased both the ultimate anaerobic biodegradability and the methanization rate. The ultimate biodegradability was
increased from 66 to 86% for sorghum and from 56 to 72% for wheat straw. The first order kinetic constant for methane production was increased by 33% (from 0.21 to 0.28 d-1) for sorghum and by 170% (from 0.10 to 0.27 d-1) for wheat straw
Comparison of various post-treatments for recovering methane from agricultural digestate
No full textAt full scale biogas plants, a large amount of digestate, which still contains a residual methane potential, is produced daily. Problems related to digestate storage and its use (i.e., biogas losses, the high cost of digestate transportation and limitations imposed by the European Nitrate Directive on its use as soil amendment) have attracted great attention among researcher to find solutions to take advantage of its residual methane potential. Thus, the aim of this study was to evaluate the methane production from digestate (DIG) and solid separated digestate (SS-DIG) and the feasibility of applying different kinds of post-treatments (i.e., thermal, thermo-chemical and enzymatic) in order to enhance their methane recovery. Results revealed that the methane recovery from digestate and solid separated digestate is feasible, considering their residual methane yields (70 NmL CH4/g VS and 90 NmL CH4/g VS, respectively). Thermal and alkaline post-treatments did not have a beneficial effect in enhancing methane potentials, while enzymatic post-treatment resulted in an increase of methane yield of 13% and 51% for SS-DIG and DIG samples, respectively. Finally, digestate recirculation permitted to obtain an extra electrical production (up to 4818 kWhel/day), which could represent an extra economical income to farmers
Sodium hydroxide pretreatment of ensiled sorghum forage and wheat straw to increase methane production
No full textThe aim of this study was to determine the effect of sodium hydroxide pretreatment on the chemical
composition and the methane production of ensiled sorghum forage and wheat straw. NaOH
pretreatment was conducted in closed bottles, at 40 WC for 24 h. Samples were soaked in a NaOH
solution at different dosages (expressed in terms of total solids (TS) content) of 1 and 10% gNaOH/gTS,
with a TS concentration of 160 gTS/L. At the highest NaOH dosage the reduction of cellulose,
hemicelluloses and lignin was 31, 66 and 44%, and 13, 45 and 3% for sorghum and wheat straw,
respectively. The concentration of soluble chemical oxygen demand (CODs) in the liquid phase after
the pretreatment was also improved both for wheat straw and sorghum (up to 24 and 33%,
respectively). Total sugars content increased up to five times at 10% gNaOH/gTS with respect to
control samples, suggesting that NaOH pretreatment improves the hydrolysis of cellulose and
hemicelluloses. The Biochemical Methane Potential (BMP) tests showed that the NaOH pretreatment
favoured the anaerobic degradability of both substrates. At 1 and 10% NaOH dosages, the methane
production increased from 14 to 31% for ensiled sorghum forage and from 17 to 47% for wheat straw.
The first order kinetic constant increased up to 65% for sorghum and up to 163% for wheat straw
Process for obtaining copper-enriched cells of Saccharomyces cereviasiae
No full textThe research was aimed at obtaining copper-enriched cells of Saccharomyces cerevisiae, developing an efficient metal delivery system for human nutrition and therapeutic treatments. To produce glutathione (GSH)–copper conjugates, four samples of commercial baker’s yeasts (S. cerevisiae) were employed in biotransformation trials with copper acetate. GSH production was found variable, ranging from 0.15 to 1.2% cell dw. Trials carried out with copper-adapted cells resulted in GSH and conjugate limited biosynthesis.
The highest copper conjugate level (1.7% dw) was instead obtained in experiments set up by employing not adapted cells. Cell disruption by sonication and subsequent analysis by atomic absorption
evidenced the presence of very interesting amount of intracellular copper, 1.8±0.2 mg/g celldw (i.e. 28 mol copper/g cell dw). The proposed procedure can be considered an interesting opportunity to further the range of application of yeast cells culture, for the set up of a copper delivery system for therapeutic treatments
Antimicrobial activity of lysozyme and lactoferrin incorporated in cellulose-based food packaging
No full textThe antimicrobial proteins lysozyme and lactoferrin were incorporated into paper containing carboxymethyl
cellulose, that allowed non-covalent binding of the positively charged proteins to the paper
matrix. More than 60 percent of the proteins added alone or in combination during the papermaking
process were released in buffered saline.
The released proteins retained their structural and functional features, indicating that the papermaking
process did not affect their structure. The antimicrobial activity on common food contaminants
was also retained in the released protein, and a synergism between the two proteins was evident in tests
carried out with paper containing both proteins against Listeria.
Tests on thin meat slices laid on paper sheets containing either or both antimicrobial proteins indicated
that lysozyme was most effective in preventing growth of this particular microbiota
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