Identification of Thiols in Yellow Onion (Allium cepa L.) Using Solvent Vented Large Volume Injection GC‐MS

Thiols are often highly odor active molecules and as such can significantly contribute to aroma while being present at extremely low concentrations. This paper details the identification of thiols in yellow onion juice by solvent extraction followed by thiol enrichment using a mercuric agarose gel column. Due to the inherent thermal instability and low concentrations of thiols in onion, chromatographic analysis utilized larger volume solvent elimination injections. New sulfur compounds in onion included 1,1‐propanedithiol, bis‐(1‐sulfanylpropyl)‐sulfide, 1‐methylsulfanyl‐1‐propanethiol, 1‐propylsulfanyl‐1‐propanethiol, and 1‐allylsulfanyl‐1‐propanethiol. A discussion on the potential route of formation for each compound is included along with the orthonasal and retronasal evaluations of the synthesized molecules. This work investigated and identified 5 newly identified compounds present in onions that can impart onion character at low concentrations levels.     

Analysis of monotonic greening and browning trends from global NDVI time-series

Remotely sensed vegetation indices are widely used to detect greening and browning trends; especially the global coverage of time-series normalized difference vegetation index (NDVI) data which are available from 1981. Seasonality and serial auto-correlation in the data have previously been dealt with by integrating the data to annual values; as an alternative to reducing the temporal resolution, we apply harmonic analyses and non-parametric trend tests to the GIMMS NDVI dataset (1981-2006). Using the complete dataset, greening and browning trends were analyzed using a linear model corrected for seasonality by subtracting the seasonal component, and a seasonal non-parametric model. In a third approach, phenological shift and variation in length of growing season were accounted for by analyzing the time-series using vegetation development stages rather than calendar days. Results differed substantially between the models, even though the input data were the same. Prominent regional greening trends identified by several other studies were confirmed but the models were inconsistent in areas with weak trends. The linear model using data corrected for seasonality showed similar trend slopes to those described in previous work using linear models on yearly mean values. The non-parametric models demonstrated the significant influence of variations in phenology; accounting for these variations should yield more robust trend analyses and better understanding of vegetation trends.     

Triple bioaffinity mass spectrometry concept for thyroid transporter ligands

For the analysis of thyroid transporter ligands, a triple bioaffinity mass spectrometry (BioMS) concept was developed, with the aim at three different analytical objectives: rapid screening of any ligand, confirmation of known ligands in accordance with legislative requirements, and identification of emerging yet unknown ligands. These three purposes share the same biorecognition element, recombinant thyroid transport protein transthyretin (rTTR), and dedicated modes of liquid chromatography-mass spectrometry (LC-MS). For screening, a rapid and radiolabel-free competitive inhibition MS binding assay was developed with fast ultrahigh performance-liquid chromatography-electrospray ionization-triple-quadrupole-MS (UPLC-QqQ-MS) as the readout system. It uses the nonradioactive stable isotopic thyroid hormone (13)C(6)-l-thyroxine as the label of which the binding to rTTR is inhibited by any ligand such as thyroid drugs and thyroid endocrine disrupting chemicals (EDCs). To this end, rTTR is either used in solution or immobilized on paramagnetic microbeads. The concentration-dependent inhibition of the label by the natural thyroid hormone l-thyroxine (T4), as a model analyte, is demonstrated in water at part-per-trillion and in urine at part-per-billion level. For confirmation of identity of known ligands, rTTR was used for bioaffinity purification for confirmation of naturally present free T4 in urine. As a demonstrator for identification of unknown ligands, the same rTTR was used again but in combination with nano-UPLC-quadrupole time-of-flight-MS (nLC-Q-TOF-MS) and urine samples spiked with the model "unknown" EDCs triclosan and tetrabromobisphenol-A. This study highlights the potential of BioMS using one affinity system, both for rapid screening and for confirmation and identification of known and unknown emerging thyroid EDCs.     

The actin content of different muscles from beef and pork

In the literature 3-methylhistidine (3-MeHis) is mentioned as a parameter for the determination of meat content. Because of the variable molar ratio of 3-MeHis in the myofibrillar protein myosin, this indicator cannot be used without some restriction. However, the content of 3-MeHis in the myofibrillar protein actin is constant. Moreover, actin is relatively heat-stable in comparison with other muscle proteins. These facts made actin an interesting parameter for determination of the meat (protein) content of heated and raw meat products.

Fast protein liquid chromatography (FPLC) was used to separate from a meat extract an actin-containing fraction without myosin. The actin content of the meat was calculated from its content in the fraction. The latter was determined by means of a 3-MeHis method.

Several muscles of the beef and pig carcass were examined for their actin contents. Generally, the actin values were comparable with the data reported in the literature.

The influence of heat treatment was also studied on one type of beef muscle. The determined actin content was not affected up to a temperature of 85°C.     

Private sector involvement in financing and operating transport infrastructure

The key role of transport infrastructure in the emerging European network has provoked many questions as to the financing and operating of existing and new transport infrastructure. In the course of the twentieth century governments in all countries have assumed responsibility for financing and operating transport infrastructure. In the past decade, however, serious doubts have been expressed on the efficiency of a strong public financial involvement in infrastructure. The paper addresses the question whether infrastructure financing and operation is a necessary competence of governments. In principle, infrastructure may be provided by the private sector, through which efficiency gains may be achieved. Therefore, the necessity for government financing is at stake in the current debate. In the paper several arguments for and against private financing are systemically evaluated and illustrated by diverse uses related to various modes of transport. The conclusion is that there is much scope for the private sector in financing and operating new and existing transport infrastructures in Europe.     

Analytical Model for Fracture Grouting in Sand

A conceptual, analytical model has been developed to describe the fracture grouting process in sand. The objective of the model is to improve understanding about this process in sand and to model propagation of the fractures. The results can be used to assess the parameters that control the fracture process. It is assumed that the complicated shape of a fracture in sand can be simplified to a geometrical shape (such as a tube or a plane) as a first approximation. Filtration of the grout appears to have a significant influence on the fracture shape when grout is injected into permeable subsoil such as sand. By assuming a pressure at which a fracture starts and a minimum pressure for propagation, it appeared possible to calculate the width-to-length ratio of the fracture independent of other soil properties. Quantification of the flow inside a fracture and the filtration processes resulted in a model that has been used to study differences in fracturing behavior in model tests and field tests on fracture grouting in sand. It was concluded that the width-to-length ratio of the fractures in a permeable soil decreases if the injection pressure of the grout or the permeability of the grout cake is decreased.     

Synthesis of 3'-phosphates of diribonucleoside monophosphates via phosphotriester intermediates

Phosphorylation of the easily accessible 3',5'-diesters 1a-d with diphenyl phosphorochloridate, followed by selective 5'-deacylation, affords the phosphotriester derivatives 2a-d in good yields. Alkaline treatment of 2a-d results in the formation of the 2',3'-cyclic phosphates (3a-d). The usefulness of the phosphotriester derivatives 2a-d is also demonstrated in the synthesis of the nucleotidyl-(3'-5')nucleoside 3'-phosphates U-Up (10a), U-Ap (11a), U-Cp (12a) and A-Gp (13a). The fully protected dinucleoside diphosphates 5c-8c, prepared by the phosphotriester method, are deprotected in two ways: (a) by a purely chemical method, affording the dinucleoside diphosphates in a circa one to one mixture of 2'- and 3'- isomers, 10b-13b and 10a-13a, respectively, and (b) by a mixed chemical-enzymatical approach which gives the pure 3'-phosphates (10a-13a).     

Fast biosensor immunoassays for the detection of cows' milk in the milk of ewes and goats

Two monoclonal antibodies (MAb) raised against bovine kappa-casein were developed and applied in an automated optical biosensor (Biacore 3000) to create easy and fast direct and inhibition biosensor immunoassays (BIA) for the detection of cows' milk in the milk of ewes and goats. With both assay formats, low limits of detection (<01%) and fast run times (around 5 min) were obtained. For sample preparation, milk was diluted in buffer (direct assay) or in an antibody-containing buffer (inhibition assay) only. For quantitative analysis, calibrants of cows' milk in ewes' or goats' milk were used. Advantages of the direct BIA are: the single reagent format (biosensor chip immobilized antibodies only); the use of small amounts of antibodies (2 microg for >350 tests); and the wide measurement range (0.1 to 10% cows' milk). Despite these advantages, the inhibition BIA (using kappa-casein immobilized on the chip) was preferred because of the possible application of non-purified Mab, the higher responses, the higher sensitivity at relevant low percentages of cows' milk and its robustness (>800 cycles per chip).     

Strategic study on the utilization of underground space in the Netherlands

In the Netherlands, interest in utilization of underground space has been increasing over the pastdecade. To examine the potential for subsurface space use, a national lldStrategic Study on the Utilization of Underground Space” was carried out by the Centre for Underground Construction (Centrum Ondergrounds Bouwen, COB) and Delft University of Technology (TUD), on the initiative of the National Physical Planning Service (Rijksplanologische Dienst, RPD) of Service (Rijksplanologische Dienst, RPD) of the Ministry of Housing, Spatial Planning and the Environment. The paper describes the objectives of the study, the characteristics of underground space use in the Netherlands, positive and negative influences on the potential use of such space, and conclusion of the Strategic Study, including likely prospective applications of subsurface space in the Netherlands.