Tolerance to winemaking stress conditions of Patagonian strains of Saccharomyces eubayanus and Saccharomyces uvarum.

AIMS: Evaluating the winemaking stress tolerance of a set of both Saccharomyces eubayanus and Saccharomyces uvarum strains from diverse Patagonian habitats. METHODS AND RESULTS: Yeast strains growth was analysed under increasing ethanol concentrations; all of them were able to grow until 8% v/v ethanol. The effect of different temperature and pH conditions as well as at SO2 and hexose concentrations was evaluated by means of a central composite experimental design. Only two S. uvarum strains (NPCC 1289 and 1321) were able to grow in most stress conditions. Kinetic parameters analysed (µmax and λ) were statistically affected by temperature, pH and SO2 , but not influenced by sugar concentration. The obtained growth model was used for predicting optimal growth conditions for both strains: 20°C, 0% w/v SO2 and pH 4·5. CONCLUSIONS: Strains from human-associated environments (chichas) presented the highest diversity in the response to different stress factors. Two S. uvarum strains from chichas demonstrated to be the most tolerant to winemaking conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: This work evidenced the potential use of two S. uvarum yeast strains as starter cultures in wines fermented at low temperatures. Saccharomyces eubayanus was significantly affected by winemaking stress conditions, limiting its use in this industry.

Correction: Atomic layer deposition of Cu(i) oxide films using Cu(ii) bis(dimethylamino-2-propoxide) and water.

Correction for 'Atomic layer deposition of Cu(i) oxide films using Cu(ii) bis(dimethylamino-2-propoxide) and water' by J. R. Avila, et al., Dalton Trans., 2017, DOI: .

Atomic layer deposition of Cu(i) oxide films using Cu(ii) bis(dimethylamino-2-propoxide) and water.

To grow films of Cu2O, bis-(dimethylamino-2-propoxide)Cu(ii), or Cu(dmap), is used as an atomic layer deposition precursor using only water vapor as a co-reactant. Between 110 and 175 °C, a growth rate of 0.12 ± 0.02 Å per cycle was measured using an in situ quartz crystal microbalance (QCM). X-ray photoelectron spectroscopy (XPS) confirms the growth of metal-oxide films featuring Cu(i).

Efficacy of the dietary supplement S-adenosyl-L-methionine.

OBJECTIVE: To review existing published clinical evidence surrounding the dietary supplement SAMe (S-adenosyl-L-methionine). DATA SOURCES: The majority of information was obtained from primary published literature identified through MEDLINE search (1966-February 2001). Information was also obtained through secondary and tertiary sources when available. STUDY SELECTION AND DATA EXTRACTION: All articles identified from data sources were evaluated and all relevant information included in this review. DATA SYNTHESIS: The majority of clinical trial evidence surrounds the application of SAMe for various depressive disorders, osteoarthrits, and fibromyalgia. Sample sizes of these trials and the dose employed have varied considerably. Several reviews and at least two meta-analyses have examined the available evidence surrounding SAMe in the therapy of depression for trials completed prior to 1994 and concluded that SAMe was superior to placebo in treating depressive disorders and approximately as effective as standard tricyclic antidepressants. Much of this information exists in the form of isolated case reports or solitary clinical trials. SAMe appears to be well tolerated, with the majority of adverse effects presenting as mild to moderate gastrointestinal complaints. However, it is apparent that this agent is not without risk of more significant psychiatric and cardiovascular adverse events. Information documenting drug or food interactions with SAMe is very limited. CONCLUSIONS: Consumers should be instructed to avoid unmonitored consumption of this dietary supplement until sufficient discussion has taken place with their primary healthcare provider. Although there exists significant potential for therapeutic application of SAMe, its uncertain risk profile precludes definitive recommendation at this time. Healthcare providers and consumers should likely temper their enthusiasm for this dietary supplement until sufficient information becomes available.

Role of endogenous sulphydryls and neutrophil infiltration in the pathogenesis of gastric mucosal injury induced by piroxicam in rats.

In the present report we studied the formation of severe gastric erosions produced in fasted rats by intragastric administration of piroxicam (PRX), an enolic acid-derived NSAID. The time course of gastric damage and the possible role of mucus secretion, endogenous sulphydryl compounds, changes of gastric vascular permeability and neutrophil infiltration in the development of PRX-induced gastric lesions were also investigated. PRX dose-dependently (1.25-20 mg/kg) caused acute gastric haemorrhagic erosion in the rat. The lesions increased with time until 9 hr after dosing. Mucus secretion did not change significantly with respect to the control group with 5, 10 and 20 mg/kg of PRX at different times (3 and 6 hours) of treatment. There was also no increase in the concentration of its components. In addition, oral pretreatment of the animals with PRX did not significantly change the amount of dye trapped in the stomach. In contrast, non-protein SH fraction was decreased after administration of PRX and MPO activity as an index of neutrophil infiltration was significantly increased. These results suggest that independently of the PRX dose, depletion of endogenous non-protein SH and neutrophil infiltration could play an important part in the pathogenesis of gastric mucosal injury induced by PRX.

Formation of mutagenic activity from amino acids heated at cooking temperatures.

To investigate the formation of aromatic amine-like mutagenic activity in cooked grain foods, amino acids were heated alone or in binary combinations at either 150 or 210 degrees C. About half of the binary mixtures of arginine heated with other amino acids produced potent mutagenic responses in the Ames/Salmonella assay, but only cysteine produced mutagenic products when heated alone. One-to-one molar ratios of arginine heated with threonine, valine, cystine, cysteine or tryptophan produced reaction products that gave 1200-3200 revertants/mmol in Salmonella strain TA98 with metabolic activation. 1-Methylguanidine, a fragment of arginine, produced a mutagenic response when heated alone or in binary mixtures with all amino acids tested. Analysis of reaction product extracts by solid-phase extraction and HPLC failed to find the known heterocyclic amines commonly found in cooked meats that would explain the measured mutagenic activity. As judged by biological and chemical characterization, several new aromatic amine mutagens are formed by heating some simple amino acids combined with arginine, and these reactants may be the source of the mutagenic products detected in the extracts of some cooked grain-based foods.