Structures, orosensory activity, and T1R1/T1R3 receptor activation of amides generated by lactone aminolysis using food-related processing conditions

Aimed at the discovery of taste-active and taste-enhancing compounds formed upon food processing, a total of 16 amides were generated by aminolysis of odor-active lactones under kitchen-like, soft processing conditions using the food-related solvents ethanol, medium-chained triglycerides, and sunflower oil, respectively. Human sensory studies revealed a bitter or pungent intrinsic taste of these amides, among which N-phenethyl-4-hydroxypentanamide, N-phenethyl-(4R)-hydroxypentanamide, N-phenethyl-5-hydroxypentanamide, N-(4-hydroxy-3-methoxybenzyl)-4-hydroxypentanamide, N-(4-hydroxy-3-methoxybenzyl)-5-hydroxypentanamide, and N-(3-hydroxy-4-methoxybenzyl)-5-hydroxypentanamide also exhibited umami taste-enhancing activity in a binary mixture of monosodium l-glutamate and guanosine 5′-monophosphate. Cell-based T1R1/T1R3 taste receptor assays tendentially confirmed the umami enhancement activity, but only reached significance for N-(4-hydroxy-3-methoxybenzyl)-5-hydroxypentanamide. LC–MS/MS screening of selected amides in various fermented food products finally led to the unequivocal identification of N-phenethyl-4-hydroxypentanamide, formed by the reaction of γ-valerolactone and phenethylamine, in blue cheeses.     

Monolayer Doping via Phosphonic Acid Grafting on Silicon: Microscopic Insight from Infrared Spectroscopy and Density Functional Theory Calculations

Monolayer doping (MLD) is a promising technique for creating ultra shallow junctions (USJs). Here, a novel self assembled monolayer (SAM) grafting technique is proposed through a single oxygen atom capable of MLD. Consequently, this approach can use simple forms of alkylphosphonic acids and avoid carbon contamination altogether during the doping process. In this paper, density functional theory (DFT) is used to explore the way how alkylphosphonic acid molecules can in just one chemical step be grafted on H‐terminated Si(111). A maximum coverage of alkylphosphonic acids is found at 2/3 due to steric constrain forces. It is further demonstrated by means of in situ infrared spectroscopy and DFT calculations that the weak link of an alkylphosphonic acid, such as octadecylphosphonic acid (ODPA), is the P‐C bond, with typical release of the carbon ligand around 500 °C. Finally, after release of the carbon ligand, an unsaturated electron configuration is driving force for the phosphorous to start the MLD process.     

Flavour formation in pork semimembranosus: Combination of pan-temperature and raw meat quality

Flavour development and overall eating quality of pork semimembranosus were investigated with regard to different raw meat qualities (feeding/fasting strategy; control/low glycogen level, gender; castrate/female, slaughter live-weight; 84 kg/110 kg) combined with frying temperature (150 °C/240 °C). It was further investigated whether the precursor levels of glycogen, IMP, inosine, and hypoxanthine in the raw meat were correlated to the raw meat quality and fried/grilled attributes. Pork schnitzels were fried on a pan (155 °C) or grill–pan (240–250 °C) to a core temperature of 70 °C. Frying temperature was the one factor with greatest influence on the sensory attributes, and pan-grilled schnitzels had significantly higher scores in fried/grilled attributes regardless of meat quality compared to pan-fried schnitzels. Texture was not appreciably influenced by any treatment. There was no correlation between precursor levels and raw meat qualities or fried sensory attributes. Gender and slaughter live-weight had no pronounced influence on flavour and overall eating quality.     

Adenosine analogues as antimetabolites against Plasmodium falciparum malaria

Analogues of purine nucleosides and deoxynucleosides were tested for toxicity against the intraerythrocytic parasite Plasmodium falciparum in vitro culture. Sangivamycin (7-deaza-7-amido-adenosine) (IC37 of 0.3 microM), tubercidin (7-deaza-adenosine) (IC37 of 0.7 microM), 6-methylamino-deoxyadenosine (IC37 of 10 microM), 8-aza-2-amino-deoxy-adenosine (IC37 of 11 microM) and 2-chloro-adenosine (IC37 of 11 microM) were found to be the most toxic towards the parasite. Structure-activity analysis suggested that alteration of the purine ring at the 7 or 8 position significantly increased the toxicity of the compound against P. falciparum. Analysis by HPLC of parasite lysates which had been subjected to the cytotoxic compounds confirmed that alterations in the flux of the purine salvage pathways of the parasite had occurred. Comparison of the toxicity of these compounds against P. falciparum with the toxicity against a similar intraerythrocytic parasite, Babesia bovis, or human melanoma cell lines indicated a differential toxicity, in that many of the compounds toxic towards P. falciparum were relatively non-toxic towards human melanoma cell lines or B. bovis and vice versa. The mechanism of toxicity of the deoxyadenosine and adenosine analogues, whose normal metabolism involves transport, metabolism and incorporation into nucleic acids appears to vary significantly between P. falciparum, B. bovis and mammalian cells.     

Interaction-centric modeling of process choreographies

With the rise of electronic integration between organizations, the need for a precise specification of interaction behavior increases. Information systems, replacing interaction previously carried out by humans via phone, faxes and emails, require a precise specification for handling all possible situations. Such interaction behavior is described in process choreographies. While many proposals for choreography languages have already been made, most of them fall into the category of interconnection models, where the observable behavior of the different partners is described and then related via message flow. As this article will show, this modeling approach fails to support fundamental design principles of choreographies and typically leads to modeling errors. This motivates an alternative modeling style, namely interaction modeling, for overcoming these limitations. While the main concepts are independent of a concrete modeling language, iBPMN is introduced as novel interaction modeling language. Formal execution semantics are provided and a comprehensive toolset implementing the approach is presented.     

From "nano-bags" to "micro-pouches". Understanding and tweaking flocculation-based processes for the preparation of new nanoparticle-composites

The control of simple parameters involved in the process of classic bridging flocculation allow the preparation and fine-tuning a new class of hybrid nanomaterials with respect to size, composition, and morphology. The resulting nanoparticle-filled "nano-bags" are obtained in aqueous suspension by mixing three basic components, a polyelectrolyte, a multivalent ion, and nanoparticles in different ratios. The size range in which nano- and micropouches can be prepared seems to start at about 25 nm; these are oligo-nanoparticle aggregates whose size are clearly related to the size of the nanoparticles themselves and seem to extend up to about 5 microm. By controlling the stoichiometric balance between the global number of positive and negative charges on the polycation and on the multivalent anion and by controlling the absolute concentrations and the ratios, namely of the polyelectrolyte and the nanoparticles, one has access to a wide range of different nanopouch morphologies and compositions. Interestingly, the process of nanopouch formation seems not to be restricted to a single type of nanoparticles since, at least, citrate-stabilized gold and iron oxide nanoparticles showed indistinguishable results in transmission electron microscopy. The outer surface of the nanoparticle-filled nanopouches is easily functionalized further through layer-by-layer assembly. As a first example, we have enhanced the stability of nanopouch suspensions at increased ionic strength by electrostatic adsorption of a polyanion on the nanobag exterior.     

Drought Governance in Transition: a Case Study of the Meuse River Basin in the Netherlands

Water Resources Management - The Netherlands is internationally renowned for its flood risk management, but three consecutive dry years between 2018–2020 fuelled the debate on how to deal...     

ADVANCED GRINDING PROCESSES FOR SURFACE STRENGTHENING OF STRUCTURAL PARTS

Grinding processes are generally utilized for finishing hard and brittle materials with a view to achieving both high accuracies and stock removal rates. As a result of the mechanisms involved in grinding hardened steels, virtually all of the input mechanical energy is transformed into heat energy. When grinding hardened parts, the proportion of heat entering the work-material can lead to thermal damage, but in grinding unhardened materials it may be possible to use the heat for surface hardening of components. This paper deals with the investigation toward proving this idea as a realistic possibility. The primary experiments prove that advanced grinding processes are suitable for surface strengthening of soft-annealed or tempered parts. This new kind of heat treatment process called “grind-hardening” will be illustrated in this paper.