Microscale sample deposition onto hydrophobic target plates for trace level detection of neuropeptides in brain tissue by MALDI-MS

A sample preparation method that combines a modified target plate with a nanoscale reversed-phase column (nanocolumn) was developed for detection of neuropeptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A gold-coated MALDI plate was modified with an octadecanethiol (ODT) self-assembled monolayer to create a hydrophobic surface that could concentrate peptide samples into a ∼200–500-µm diameter spot. The spot sizes generated were comparable to those obtained for a substrate patterned with 200-µm hydrophilic spots on a hydrophobic substrate. The sample spots on the ODT-coated plate were 100-fold smaller than those formed on an unmodified gold plate with a 1-µl sample and generated 10 to 50 times higher mass sensitivity for peptide standards by MALDI-TOF MS. When the sample was deposited on an ODT-modified plate from a nanocolumn, the detection limit for peptides was as low as 20 pM for 5-µl samples corresponding to 80 amol deposited. This technique was used to analyze extracts of microwave-fixed tissue from rat brain striatum. Ninety-eight putative peptides were detected including several that had masses matching neuropeptides expected in this brain region such as substance P, rimorphin, and neurotensin. Twenty-three peptides had masses that matched peaks detected by capillary liquid chromatography with electrospray ionization MS. 1 2 Copyright © 2005 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48772/1/916_ftp.pd

Ukraine’s unconsidered losses from the annexation of Crimea: What should we account for in the DCFTA forecasts?

In March 2014 Crimea unilaterally declared its independence from Ukraine and joined the Russian Federation. The separation of a part of a state's territory and economy is an interesting matter to look into. Not only the economy of Ukraine has shrunk, it has also changed its structure as Crimea had a quite distinct production pattern compared to the rest of Ukraine. Moreover, policy measures that have been initialized before the separation may have different effects once applied only to a part of the former economy. This paper proposes a strategy to model the separation of part of an economy and its inclusion into another country and applies this strategy to the case of Crimea, Ukraine and Russia. After having constructed a model for the new geographical and economic situation we re-investigate the possible effects of a Deep and Comprehensive Free Trade Agreement (DCFTA) between Ukraine and the EU and compare the results for the situation with Crimea as part of Ukraine. We find that the annexation of Crimea leads to severe economic losses for Ukraine which are partly over-proportional compared to Crimea's economic size. These negative effects can be compensated by implementing the DCFTA with the EU as we also show in our model results