Autoproteolytic fragments are intermediates in the oligomerization/aggregation of the Parkinson's disease protein alpha-synuclein as revealed by ion mobility mass spectrometry

Gas-phase protein separation by ion mobility: With its ability to separate the Parkinson's disease protein α-synuclein and its autoproteolytic products-despite the small concentrations of the latter-ion-mobility MS has enabled the characterization of intermediate fragments in in vitro oligomerization-aggregation. In particular, a possible key fragment, the highly aggregating C-terminal fragment, αSyn(72-140), has been revealed.     

Separation of alkanes and alcohols with supercritical fluids. Part I: Phase equilibria and viability study

The chemical conversion of detergent range alkanes (12-14 carbon atoms) to alcohols is often incomplete and results in a large amount of residual alkane. This paper shows that these alkanes and alcohols can be separated by supercritical fluids. Ethane, propane and carbon dioxide were selected as possible supercritical solvents while n-tetradecane and 1-dodecanol were selected to represent the alkane-alcohol mixture, as these would be the two most difficult compounds to separate in a C12 to C14 alkane-alcohol mixture. A phase behaviour study and relative solubility analysis revealed that both ethane and carbon dioxide show promise in separating n-tetradecane and 1-dodecanol. Propane was eliminated as possible solvent because the phase behaviour of n-tetradecane and 1-dodecanol in supercritical propane is too similar. A pilot plant study showed that both supercritical ethane and carbon dioxide can be used to separate n-tetradecane and 1-dodecanol, with indications that supercritical ethane may affect a superior separation. An economic analysis, considering the energy requirements, revealed that the most important parameter with regard to energy consumption is the solvent-to-feed ratio. The process utilising ethane is more energy intensive, yet the energy requirements for both processes compare well with other petrochemical separation processes using supercritical fluids. Further investigations with both ethane and carbon dioxide should be conducted to determine which of these two solvents are superior and to optimise the operating parameters.     

Numerical simulation and validation of gas-particle rectangular jets in crossflow

This paper presents a numerical study of a gas-particle flow in three inclined rectangular jets in crossflow. The predicted gas phase velocities and particle phase velocities are validated against previously reported experimental data. Two turbulence models, the standard k-? model and Shear Stress Transfer (SST) model, are used to model the gas phase turbulence. This work shows that both models provide acceptable predictions of the gas flow and mixing generated by the three jets. Neither model could accurately reproduce the jet core and the flow near bottom wall. The particle phase in this flow comprises a large number of small particles. Thus particles follow the gas phase flow closely and any errors in the turbulence model and gas flow predictions are passed on to the particle phase simulation. This paper also includes a literature review on rectangular jets in crossflow and gas-particle laden jets in crossflow.     

Dietary n-3 Fatty Acids Significantly Suppress Lipogenesis in Bovine Muscle and Adipose Tissue: A Functional Genomics Approach

Changes in fatty acid composition of longissimus muscle and subcutaneous adipose tissue of German Holstein bulls induced by a grass-silage/n-3 fatty acid based intervention diet versus a maize-silage/n-6 fatty acid based control diet were analyzed and related to shifts in lipogenic gene expression, protein expression, and enzyme activity patterns. Significantly higher amounts of n-3 fatty acids and by mean factors of 2.2–2.5 decreased n-6/n-3 fatty acid ratios in both tissues were obtained upon n-3 fatty acid intervention. In longissimus muscle, these changes of fatty acid profiles were associated with reduced SREBP1c (p = 0.02), ACC (p = 0.00), FAS (p = 0.10) and SCD (p = 0.03) gene expression, Δ6D (p = 0.03) and SCD (p = 0.03) protein expression as well as SCD enzyme activity (p = 0.03). In subcutaneous adipose tissue, significantly reduced ACC (p = 0.00) and FAS (p = 0.01) gene expression, SCD protein expression (p = 0.02) and SCD enzyme activity (p = 0.03) were detected upon n-3 fatty acid intervention, although lower degrees of correlation between gene and corresponding gene products were obtained in relation to longissimus muscle. The study elucidates tissue-specific functional genomic responses to dietary fatty acid manipulation in regard to fatty acid profile tailoring of animal tissues.     

Metal‐Free,Radical Addition to Alkenes via Desulfitative Chlorine Atom Transfer

An efficient method for radical additions to unactivated alkenes via desulfitative chlorine‐atom transfer is described. The reaction is based on the use of readily available sulfonyl chlorides as starting materials and cheap radical initiators such as azobisisobutyronitrile (AIBN), di‐tert‐butyldiazene (DTBD), and dilauroyl peroxide (DLP). No transition metal catalyst is required and the reaction takes place under mild conditions at temperatures ≤85 °C.     

Knowledge‐Based Conceptual Synthesis of Industrial‐Scale Downstream Processes for Biochemical Products

A generic, knowledge‐based guideline assisting downstream process synthesis for biochemical products is presented. It offers process designers a structured process design methodology supporting them in capturing potentially relevant information, which might be beyond their expertise. The guideline is based on heuristic knowledge which was collected, structured in a generic way, and clearly represented. The generation of alternative downstream routes as starting points for experiments, simulation, and cost calculation is hereby accelerated. The application of the guideline is demonstrated on the example of penicillin V downstream processing from fermentation broth.     

Characteristics of carcass composition,fat metabolism and meat quality of genetically different pigs

The aim of the study was to quantify the differences in meat and fat quality and lipid metabolism of pigs with either high or medium capacity for lipid accretion. A total of 58 castrated males of the breeds German Saddle Back (SB) and German Landrace (DL) were included in the experiment. Animals were housed individually and fed twice daily semi ad libitum. Saddle Back pigs indicated a lower lean meat content (41.4% vs 52.6%) and a higher fat percentage (40.9% vs 28.2%) in comparison to DL as a result of high lipid accumulation. The larger fat content of SB was related to an increased intramuscular fat concentration of longissimus muscle. A significant correlation between intramuscular fat content and fatty acid composition was estimated in both breeds. The relative concentration of saturated fatty acids was significantly increased in SB pigs. The percentage of polyunsaturated fatty acids (8.3%) in SB muscle fat was significantly lower than in DL muscle fat (10.7%). The de novo biosynthesis of fatty acids resulted in mostly saturated fatty acids and oleic acid. The higher activities of lipogenetic enzymes in backfat of SB proved a higher lipogenetic capacity. There were no significant differences in meat quality traits of longissimus muscle between the two breeds.     

Chemical Stability of α‐Tocopherol in Colloidal Lipid Particles with Various Morphologies

Colloidal lipid particles (CLPs) are promising encapsulation systems for lipophilic bioactives, such as oil‐soluble antioxidants that are applied in food and pharmaceutical formulations. Currently, there is no clear consensus regarding the relation between particle structure and the chemical stability of such bioactives. Using α‐tocopherol as a model antioxidant, it is shown that emulsifier type (Tween 20 or 40, or sodium caseinate) and lipid composition (tripalmitin, tricaprylin, or combinations thereof) modulated particle morphology and antioxidant stability. The emulsifier affects particle shape, with the polysorbates facilitating tripalmitin crystallization into highly ordered lath‐like particles, and sodium caseinate resulting in less ordered spherical particles. The fastest degradation of α‐tocopherol is observed in tripalmitin‐based CLPs, which may be attributed to its expulsion to the particle surface induced by lipid crystallization. This effect is stronger in CLPs stabilized by Tween 40, which may act as a template for crystallization. This work not only shows how the architecture of CLPs can be controlled through the type of lipid and emulsifier used, but also gives evidence that lipid crystallization does not necessarily protect entrapped lipophilic bioactives, which is an important clue for encapsulation system design. Practical Applications: Interest in enriching food and pharmaceutical products with lipophilic bioactives such as antioxidants through encapsulation in lipid particles is growing rapidly. This research suggests that for efficient encapsulation, the particle architecture plays an important role; to tailor this, the contribution of both the lipid carrier and the emulsifier needs to be considered.     

Extraction of Algal Lipids and Their Analysis by HPLC and Mass Spectrometry

Algae are a promising source of biofuel but claims about their lipid content can be ambiguous because extraction methods vary and lipid quantitation often does not distinguish between particular lipid classes. Here we compared methods for the extraction of algal lipids and showed that 2-ethoxyethanol (2-EE) provides superior lipid recovery (>150–200 %) compared to other common extraction solvents such as chloroform:methanol or hexane. Extractions of wet and dry algal biomass showed that 2-EE was more effective at extracting lipids from wet rather than dried algal pellets. To analyze lipid content we used normal-phase HPLC with parallel quantitation by an evaporative light scattering detector and a mass spectrometer. Analysis of crude lipid extracts showed that all major lipid classes could be identified and quantified and revealed a surprisingly large amount of saturated hydrocarbons (HC). This HC fraction was isolated from extracts of bioreactor-grown algae and further analyzed by HPLC/MS, NMR, and GC/MS. The results showed that the sample consisted of a mixture of saturated, straight- and branched-chain HC of different chain lengths. These algal HC could represent an alternative biofuel to triacylglycerols (TAG) that could feed directly into the current petroleum infrastructure.