פרסומים

Noble-gas hydrides have been extensively studied in noble gas matrices. However, little is known on their stability and properties in molecular hosts. Here, HXeBr in the N-2 environment is modeled at the B3LYP-D level of theory in a complete single shell of 22 N-2 molecules. The system is compared to similar models of HXeBr in CO2 and Xe clusters. The optimized structure of (HXeBr)@(N-2)(22) is of low symmetry and is highly anisotropic. None of the N-2 molecules are freely rotating, and the host molecules are not symmetrically positioned with respect to the HXeBr axis. The axes of the N-2 molecules are nonuniformly distributed. The computed anharmonic H-Xe stretching frequency of HXeBr in the N-2 cluster is in good accord with the experimental value. The soft mode frequencies of the cluster including both intermolecular vibrations and librations, have a broad distribution that ranges from 8.7 to 107 cm(-1). It is expected that these findings and specifically, the single-shell model, may shed light also on the local structure and vibrations of other impurities in a molecular media.

Many of the world’s crops are pollinated by insects, and bees are often assumed to be the most important pollinators. To our knowledge, our study is the first quantitative evaluation of the relative contribution of non-bee pollinators to global pollinator-dependent crops. Across 39 studies we show that insects other than bees are efficient pollinators providing 39% of visits to crop flowers. A shift in perspective from a bee-only focus is needed for assessments of crop pollinator biodiversity and the economic value of pollination. These studies should also consider the services provided by other types of insects, such as flies, wasps, beetles, and butterflies—important pollinators that are currently overlooked.Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25–50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.

Measuring and monitoring of protein oxidn. modifications is important for biopharmaceutical process development and stability assessment during long-term storage. Currently available methods for biomols. oxidn. anal. use time-consuming peptide mapping anal. Therefore, it is desirable to develop high-throughput methods for advanced process control of protein oxidn. Here, we present a novel approach by which oxidative protein modifications are monitored by an indirect potentiometric method. The method is based on adding an electron mediator, which enhances electron transfer (ET) between all redox species and the electrode surface. Specifically, the procedure involves measuring the sharp change in the open circuit potential (OCP) for the mediator system (redox couple) as a result of its interaction with the oxidized protein species in the soln. Application of Pt and Ag/AgCl microelectrodes allowed for a high-sensitivity protein oxidn. anal. We found that the Ru(NH3)2+/3+6 redox couple is suitable for measuring the total oxidn. of a wide range of therapeutic proteins between 1.1 and 13.6%. Accuracy detd. by comparing with the known percentage oxidn. of the ref. std. showed that percentage oxidn. detd. for each sample was within ±20% of the expected percentage oxidn. detd. by mass spectrometry. [on SciFinder(R)]

A novel method is proposed for correcting metal fraction concentrations remaining within the sediment containing the solid residue of the sequentially extracted fraction. An easy-to-use Excel spreadsheet was prepared to assist adjustment of concentration in each fraction and demonstrate the difference between adjusted and non-adjusted metal concentration of the fraction. The demonstration of a calculation of the modified BCR protocol data showed that this difference may reach 10–15% of the result value. The spreadsheet is available to download at: http://departments.agri.huji.ac.il/zabam/Rosen_Chen_Fraction_Adjustment_.... Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

BackgroundFuran fatty acids (F-acids) are valuable minor fatty acids which are appraised for their protective role against lipid oxidation of polyunsaturated fatty acids (PUFAs). The most relevant dietary source for F-acids is fish with the predominant occurrence of up to five dimethyl- or monomethyl-substituted homologues. During the screening of fish from a zero discharge aquaculture (ZDA) system we noted the potential presence of unusual F-acids. Methods We developed a method by gas chromatography with mass spectrometry operated in the selected ion monitoring mode for elucidation of the structures of the uncommon F-acids. Results Carp from the ZDA system contained seven non-methylated F-acids with dominance of 8-(5-hexylfuran-2-yl)-octanoic acid (8F6). Non-methylated F-acids have never been detected before in fish. Subsequent analysis of other fish species and a batch of the fish feed confirmed the presence of non-methylated F-acids. Conclusions F-acids in fish are derived from the feed. Our investigation indicates that more emphasis should be put on the F-acid concentrations in fish from aquaculture, which appears to depend on the quality of the fish feed.

The tumor-suppressor p53 is a transcription factor that prevents cancer development and is involved in regulation of various physiological processes. This is mediated both by induction of cell cycle arrest and apoptosis and by controlling the expression of a plethora of target genes, including secreted proteins. It has been demonstrated that p53 may exert its effect in non-cell-autonomous manner by modulating the expression of genes that encode for secreted factors. In this study, we utilized our microarray data to identify and characterize novel p53 target genes expressed in human liver cells and associated with steroid hormones processing and transfer. We identified the steroid hormones binding factors, sex hormone-binding globulin (SHBG), corticosteroid-binding globulin (CBG) and cytochrome P450 family 21 subfamily A polypeptide 2, as novel p53 target genes. Their expression and secretion was increased following p53 activation in various hepatic cells. We observed that p53 wild-type mice exhibited higher levels of CBG compared with their p53 null counterparts. We demonstrated that the induction of the steroid hormones binding factors can be mediated by binding to specific p53 responsive elements within their promoters. In addition, utilizing conditioned medium experiments we have shown that p53-dependent induction of SHBG secretion from liver cells enhances apoptosis of breast cancer cells. Moreover, depletion of SHBG abolished the induction of breast cancer cells death. The newly identified p53 target genes suggest a novel non-cell-autonomous tumor-suppressive regulation mediated by p53 that is central for maintaining organism homeostasis.