A Headspace–SPME–MS Method for Monitoring Rapeseed Oil Autoxidation

Headspace SPME–MS was used to analyze volatile compounds from rapeseed oil subjected to an accelerated storage test consisting of 0–12 days of storage at 60 °C. The SPME–MS data was compared with the data obtained by solid phase microextraction–gas chromatography/mass spectrometry (SPME–GC/MS). The SPME–GC/MS method allowed detection of 37 volatile compounds, of which 28 were identified. Predominant ones were hexanal, 2,4-heptadienal, 2-heptenal and 1-pentene-3-ol. Volatile compounds were not separated in SPME–MS—a single peak reflecting the total amount of volatiles was obtained. An increase in the abundance of characteristic ions in this peak could be used to detect of compounds characteristic for rapeseed oil autoxidation. These compounds (with their characteristic ions) were hexanal (m/z 56), 1-pentene-3-ol and 1-octene-3-ol (m/z 57), 2-pentenal and 2-heptenal (m/z 83 and 84), and 2,4-heptadienal (ions m/z 81 and 110). The SPME–MS peak area was correlated with peroxide value at 0.9779 and with Totox at 0.9841. Principal component analysis (PCA) of fatty acid volatile oxidation products from a model rapeseed oil indicated that SPME–MS was able to differentiate samples containing hexanal at a concentration of 0.2, 0.4, 0.6, 0.8 and 1.0 mg/L with proportional amounts of other compounds. Further, samples that were subjected to 0, 2, 4, 6, 8, 10 and 12 days of storage at 60 °C were differentiated using SPME–MS–PCA. PCA showed similarities in clustering of the data obtained by SPME–MS and sensory analysis.     

Photocatalytic Reaction of Diazo Compounds with Aldehydes

Photocatalytic reactions of diazoacetates with aldehydes led to α‐alkylated carbonyl compounds instead of the expected cyclopropane derivatives. The reaction requires a dual catalytic system – photocatalysis merged with enamine‐iminium catalysis. NMR, EPR, UV/Vis, and ESI‐MS analyses provided sufficient data to corroborate the proposed radical mechanism – enamine catalysis merged with photocatalysis.

     

Successful management of right coronary air embolus after intracoronary administration of verapamil

The incidence of classic Kaposi's sarcoma (CKS) has been reported to be high in Jewish populations living in Israel and in immigrants originating from the Mediterranean basin. No population-based reports are available on the incidence of CKS in Israeli Arabs. We analyzed the incidence of CKS cases occurring between 1970 and 1993 among Arabs living in Israel. Reporting systems were the Israel Cancer Registry, the medical documentation of all-Kaposi's sarcoma cases and the registry of human immunodeficiency virus-seropositive patients. Population figures were derived for census surveys (1972 and 1983) and inter-census data based on annual updating of demographic characteristics. Age-standardized incidence rates (ASR) were 6.87 per million in men and 2.18 per million in women. The ASR did not increase between 1970 and 1993 in either men or women. The age-adjusted male to female ratio was 2.0 below 50 years of age and 3.5 above it. The observation of a stable and relatively high incidence of CKS in Israel-born Arabs, comparable to other populations living in the Mediterranean basin, suggests that risk is related to geographical origin. CKS incidence, however, is lower than that in Israel-born Jews.     

Functional analysis of three adjacent open reading frames from the right arm of yeast chromosome XVI

A 7.24 kb genomic DNA fragment from the yeast Saccharomyces cerevisiae chromosome XVI was isolated by complementation of a new temperature-sensitive mutation tsa1. We determined the nucleotide sequence of this fragment located on the right arm of chromosome XVI. Among the three, complete open reading frames: YPR041w, YPR042c and YPR043w contained within this fragment, the gene YPR041w was shown to complement the tsa1 mutation and to correspond to the TIF5 gene encoding an essential protein synthesis initiation translation factor. The YPR042c gene encodes a hypothetical protein of 1075 amino acids containing four putative transmembrane segments and is non-essential for growth. The gene YPR043c encoding the 10 kDa product, highly similar to the human protein L37a from the 60S ribosomal subunit, was found to be essential and a dominant lethal. We conclude that three tightly linked yeast genes are involved in the translation process.     

Activated Carbon Modified with Different Chemical Agents as a Catalyst in the Dehydration and Dehydrogenation of Isopropanol

Activated carbons modified with different chemical agents such as HNO₃, H₂SO₄, peroxyacetic acid (PAA), air, NH₃ and Cl₂ have been tested as catalysts in decomposition (dehydration and dehydrogenation) of isopropanol. The majority of the samples obtained have been characterised by well-developed microporous surface with a small contribution of mesopores (8–18%). The influence of the surface area of the samples on their catalytic performance has been insignificant. The carbon oxidation with oxidants in the liquid or gas phase leads to an increased catalytic activity and the dominant process is dehydration of the alcohol studied. Carbon modification by contact with gas ammonia or chlorine results in a decrease in the catalytic activity and a significant increase in the contribution of dehydrogenation of isopropanol. It has been shown that such behaviour of the catalysts has been a consequence of changes in the acid-base character of the carbons induced by their modification.     

Low temperature deposition of dense MnCo2O4 protective coatings for steel interconnects of solid oxide cells

In this work manganese cobalt spinel (MnCo₂O₄) coatings were deposited on steel substrates by spray pyrolysis at 390?°C. This is at much lower temperatures than previously reported (typically in excess of 900?°C). It was possible to produce coatings with well controlled thickness (2-5-10?μm). The as-deposited coatings were evaluated for their microstructural changes and electrical conductivity up to 800?°C. Results confirm the formation of a single phase spinel with high density and electrical conductivity. Based on the obtained results, it might be concluded that spray pyrolysis is a very promising method to develop protective coatings for steel substrates at low temperatures overcoming limitations of many other methods.     

Efficiency analysis of combined biomass and solar energy in Lithuania

In this paper were performed analyses of the renewable energy impact on reduction of the greenhouse gas (GHG) emissions. The pilot integrated biomass and solar water heating system at public institutions of Lithuania were analyzed. Purpose of this analysis was to evaluate systems′ efficiency of performance. It has been executed for measurements of produced energy, consumed water, and burned biofuel in summer and winter time. Analysis showed that heat load for domestic hot water is too low for biomass boiler for summer season. That problem could be improved with optimizing solar heating system. Modernization of this system could significantly reduce energy costs and emissions of carbon dioxide and demonstrate an integrated solution with bio and solar energies utilization in this system. Investigation shows that Lithuania can reduce GHG emission to 8 % in the period 2008–2012 by increasing use of biomass, solar, and others renewables and achieve the requirement of the Kyoto protocol.