Highly Stereoselective Halocyclopropanation of α,β‐Unsaturated Amides

A convenient highly stereoselective synthesis of chloro‐ and bromocyclopropanamides from di‐ tri‐ or tetrasubstituted (E)‐ or (Z)‐α,β‐unsaturated amides with total or high stereoselectivity promoted by chromium dichloride or dibromide is described. The transformation of chlorocyclopropanamides into the corresponding ketones or amines is also reported. A mechanism to explain these transformations is proposed.     

Development of an indirect α-actinin-based immunoassay for the evaluation of protein breakdown and quality loss in fish species subjected to different chilling methods

α‐Actinin release from the myofibrillar protein fraction to the sarcoplasm can be considered as an accurate proteolysis index in seafood muscle. The main objective of the present study was to develop a specific enzyme‐linked immunosorbent assay (ELISA), based on the use of a monoclonal antibody against α‐actinin to evaluate the degree of proteolysis in two different chilled fish species – European hake (Merluccius merluccius) and turbot (Psetta maxima) – kept under two different storage systems: flake ice and slurry ice. Comparison with sensory assessment, K‐value and sarcoplasmic protein profiles was carried out. A different degree of proteolysis could be observed in both fish species; thus, the immunoassay was shown to be useful in monitoring the protein degradation events in hake muscle especially under flake ice storage. In the case of turbot, as very low proteolysis development could be obtained, the assay was not suitable for assessing quality changes. A different break point of immunoassay values for each fish species is suggested.     

Optimising the inactivation of grape juice spoilage organisms by pulse electric fields

The effect of some pulsed electric field (PEF) processing parameters (electric field strength, pulse frequency and treatment time), on a mixture of microorganisms (Kloeckera apiculata, Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus hilgardii and Gluconobacter oxydans) typically present in grape juice and wine were evaluated. An experimental design based on response surface methodology (RSM) was used and results were also compared with those of a factorially designed experiment. The relationship between the levels of inactivation of microorganisms and the energy applied to the grape juice was analysed. Yeast and bacteria were inactivated by the PEF treatments, with reductions that ranged from 2.24 to 3.94 log units. All PEF parameters affected microbial inactivation. Optimal inactivation of the mixture of spoilage microorganisms was predicted by the RSM models at 35.0 kV cm^− 1 with 303 Hz pulse width for 1 ms. Inactivation was greater for yeasts than for bacteria, as was predicted by the RSM. The maximum efficacy of the PEF treatment for inactivation of microorganisms in grape juice was observed around 1500 MJ L^− 1 for all the microorganisms investigated. The RSM could be used in the fruit juice industry to optimise the inactivation of spoilage microorganisms by PEF.     

Inhibition of dipeptidyl peptidase IV by enzymatic hydrolysates derived from primary and secondary whey of fresh and Oaxaca cheeses

Currently, there is an interest in studying natural inhibitors of dipeptidyl peptidase IV (DPP‐IV) for the treatment of type II diabetes. To look for novel inhibitors, the primary and secondary whey of fresh and Oaxaca cheeses was obtained, and the electrophoretic patterns were determined. Hydrolysis with pepsin and trypsin of primary and secondary whey from fresh and Oaxaca cheeses, respectively, showed DPP‐IV inhibition with values of ~51 and 55%, and also an IC50 of 92.86 μg/mL for Oaxaca cheese‐derived peptides. Data show the potential of whey enzymatic hydrolysates from fresh and Oaxaca cheeses as antidiabetic agents.     

Comparison of the conductance of three types of porphyrin-based molecular wires: β,meso,β-fused tapes, meso-Butadiyne-linked and twisted meso-meso linked oligomers

The length dependence of charge transport is evaluated in three families of porphyrin-based wires. Planar edge-fused tapes and alkyne-linked oligomers mediate efficient charge transport with exceptionally shallow distance dependence, whereas the conductances of the twisted singly linked chains decrease steeply with increasing oligomer length. The planar tapes are more conjugated than the alkyne-linked oligomers, but these two types of wires have similar conductance attenuation factors.     

Active power filter for medium voltage networks with predictive current control

A transformer less Shunt Active Power Filter (SAPF) for medium voltage distribution networks based on Multilevel Diode Clamped Inverter is presented in this paper. Converter current control is based on a Model Predictive strategy, which gives very fast current response. Also, the algorithm includes voltage balancing capability which is essential for proper converter operation. The presented current control algorithm is naturally applicable to converters with an arbitrary number of levels with reduced computational effort by virtue of the incorporation of switching restrictions which are necessary for reliable converter operation. The performance of the proposed algorithm is evaluated by means of computer simulations.     

Comparative risk assessment of residential radon exposures in two radon-prone areas, ?tei (Romania) and Torrelodones (Spain)

Radon and radon progeny are present indoors, in houses and others dwellings, representing the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for both smokers and nonsmokers. The work presents a comparative analysis of the radon exposure data in the two radon-prone areas, ?tei, Transylvania, (Romania), in the near of old Romanian uranium mines and in the granitic area of Torrelodones town, Sierra de Guadarrama (Spain). Measurements of indoor radon were performed in 280 dwellings (Romania) and 91 dwellings (Spain) by using nuclear track detectors, CR 39. The highest value measured in ?tei area was 2650 Bq m^− 3 and 366 Bq m^− 3 in the Spanish region. The results are computed with the BEIR VI report estimates using the age-duration model at an exposure rate below 2650 Bq m^− 3. We used the EC Radon Software to calculate the lifetime lung cancer death risks for individuals groups in function of attained age, radon exposures and tobacco consumption. A total of 233 lung cancer deaths were observed in the ?tei area for a period of 13 years (1994-2006), which is 116.82% higher than expected from the national statistics. In addition, the number of deaths estimated for the year 2005 is 28, which is worth more than 2.21 times the amount expected by authorities. In comparison, for Torrelodones was rated a number of 276 deaths caused by lung cancer for a period of 13 years, which is 2.09 times higher than the number expected by authorities. For the year 2005 in the Spanish region were reported 32 deaths caused by pulmonary cancer, the number of deaths exceeding seen again with a factor of 2.10 statistical expectations. This represents a significantly evidence that elevated risk can strongly be associated with cumulated radon exposure.