Search results for "Visual arts"

Relationships between metabolic fluxes and enzyme amino acid composition

2013

AbstractMetabolic fluxes are a key parameter of metabolic pathways being closely related to the kinetic properties of enzymes and could be conditional on their sequence characteristics. This study examines possible relationships between the metabolic fluxes and the amino acid (AA) composition (AAC) for enzymes from the yeast Saccharomyces cerevisiae glycolysis pathway. Metabolic fluxes were quantified by the COPASI tool using the kinetic models of Hynne and Teusink at 25 mM, 50 mM, and 100 mM of external glucose or employing literature data for cognate kinetic or stoichiometric models. The enzyme sequences were taken from the UniProtKB, and the AAC computed by the ExPASy/ProtParam tool. Mul…

O-linked mannose composition of secreted invertase of Saccharomyces cerevisiae

1989

The secreted invertase (EC 3.2.1.26) of Saccharomyces cerevisiae is a glycoenzyme that contains N- and O-linked mannoses in 40/1 proportion. The small amount of mannose chains O-linked to invertase is distributed as follows: mannose (20%), mannobiose (50%), mannotriose (6%), mannotetraose (7%) and mannopentaose (17%).

Synthesis and characterisation of polymeric manganese and zinc 5-hydroxyisophthalates

2001

Abstract The crystallisation of 5-hydroxyisophthalic acid with divalent Mn or with Mn or Zn and either 2,2-bipyridine (2,2-bipy) or pyridine-2-(1H-pyrazol-3-yl) gave solids of composition [Mn(C8H4O5)(H2O)3]·2H2O (1), [Mn(C8H4O5)(2,2′-bipy)]·H2O (2), [Mn2(C8H4O5)2(C8H7N3)2]·H2O (3) and [Zn(C8H4O5)(2,2′-bipy)] (4). Each compound has 1D co-ordinative chains that are connected by hydrogen bonds. Compounds 2–4 contain M2C2O4 rings with pseudo-chair geometries. The Mn atoms in 2 are coupled antiferromagnetically.

Salt and fat contents influence the microstructure of model cheeses, chewing/swallowing andin vivoaroma release

2013

The effects of the lipid/protein ratio (20/28, 24/24, 28/20) and salt content of model cheeses were investigated simultaneously with respect to chewing behaviour, swallowing events and in vivo aroma release. Chewing parameters were measured by electromyography. Swallowing events were recorded manually. In vivo aroma release was investigated using nose-space on-line atmospheric pressure chemical ionisation-mass spectrometry. The values for chewing activity and time before swallowing were higher with lower lipid/protein ratios and lower salt contents, due to the greater mechanical resistance of the model cheeses. The corresponding microstructure was made up of smaller and more circular fat dr…

Chemical and physico‐chemical changes during the dry‐cured processing of deer loin

2019

The changes on chemical composition, physico‐chemical parameters, free fatty acids and free amino acids content of dry‐cured deer loin were investigated at day 0, 30 and 60 of dry‐cured process. On the whole, except for pH values (≈5.6) and composition (fat: 4.6–5.2%; protein: ≈73%; ash: ≈17.5%) that did not show differences between the processing days, the other physico‐chemical parameters were affected by curing process. Colour parameters and moisture (from 69 to 38.4%) decreased while the hardness increase from 12.35 to 342 N and lipid oxidation (from 0.2 to 0.52 mg MDA/kg) increased as dry‐cured stage progresses. In similar way, free fatty acid (2250 mg per 100 g of fat at 0 day and 594…

Stability of ascorbic acid in adapted milk-based infant formulae during storage

2004

A study was made of the effects of storage (for up to 17 months at 22 or 37 °C) on the ascorbic acid contents of four adapted milk-based infant formulae with the same composition except for the iron salt added (lactate or sulphate) and/or the vitamin E source involved (α-tocopherol (α-T) or α-tocopherol acetate (α-TAc)). Ascorbic acid was measured by a voltammetric method. The ascorbic acid contents of the formulae ranged from 0.77–0.84 g kg−1 immediately after manufacture to 0.41–0.48 g kg−1 after 17 months of storage. Samples stored at 22 °C had higher ascorbic acid contents than those stored at 37 °C. A multiple regression analysis performed to evaluate ascorbic acid evolution throughout…

The quality of Valle del Belice sheep’s milk and cheese produced in the hot summer season in Sicily

2013

In response to the growing consumer demand for fresh cheese in summer, this investigation was aimed to evaluate the chemical and microbiological characteristics of sheep’s milk and cheese produced in Sicily in the hot summer months. A total of 810 bulk milk samples collected from 17 farms rearing ewes of the Valle del Belice breed were analysed for chemical composition, somatic cell count, total bacterial count and clotting parameters. Samples (n = 18) of Protected Designation of Origin Vastedda della valle del Belice cheese produced in six dairies were collected in summer, autumn and spring and analysed for chemical composition, microbiological profile and fatty acid (FA) composition. Univ…

Cardenolides of Digitalis obscura: The effect of phosphate and manganese on growth and productivity of shoot-tip cultures

1997

Abstract Cardenolide composition of leaves from wild and micropropagated elite plants of Digitalis obscura (genotype T4) has been investigated and no qualitative differences were found among their major cardenolides (series A). All of the detected glycosides belong to the digitoxose-type cardenolides. Genins represented less than 2% of the overall content, while lanatoside A was the predominant cardenolide ( ca. 65%) in all samples. The cardenolide yield of micropropagated D. obscura plants depended on the age and development of the cultures, but productivity of long-term cultures (2 years) was quite similar to that of the parent plant. Changes in the concentrations of phosphate or manganes…

Fatty acid composition of the seed lipids ofChamaerops humilisL. natural populations and its relation with the environment

2014

Seed lipids composition is a tool to discriminate among plant taxa and is related to phylogeny and biogeographic distribution. Aim of the present study was to evaluate the fatty acid (FA) composition of the seed lipids from nine natural Chamaerops humilis L. population and its relation with the climatic traits of the collection sites. The average seed lipids content was 54.8 g kg21 and the most represented FAs were oleic (478 g kg21 oil) and linoleic (230 g kg21 oil), with significant differences among the accessions. Most of the lipid traits significantly correlated with climatic traits. In particular, oleic acid negatively correlated with year potential evapotranspiration. These relations…

2020

Biomolecules, and particularly proteins, bind on nanoparticle (NP) surfaces to form the so-called protein corona. It is accepted that the corona drives the biological distribution and toxicity of NPs. Here, the corona composition and structure were studied using silica nanoparticles (SiNPs) of different sizes interacting with soluble yeast protein extracts. Adsorption isotherms showed that the amount of adsorbed proteins varied greatly upon NP size with large NPs having more adsorbed proteins per surface unit. The protein corona composition was studied using a large-scale label-free proteomic approach, combined with statistical and regression analyses. Most of the proteins adsorbed on the N…