Alterations of Placental Sodium in Preeclampsia: Trophoblast Responses.

Background: Evidence suggests that increasing salt intake in pregnancy lowers blood pressure, protecting against preeclampsia. We hypothesized that sodium (Na) evokes beneficial placental signals that are disrupted in preeclampsia.

Methods: Blood and urine were collected from nonpregnant women of reproductive age (n=26) and pregnant women with (n=50) and without (n=55) preeclampsia, along with placental biopsies.

Gas-Phase Alkali-Metal Cation Affinities of Stabilized Enolates.

The chemistry of alkali-metal enolates is dominated by ion pairing. To improve our understanding of the intrinsic interactions between the alkali-metal cations and the enolate anions, we have applied Cooks' kinetic method to determine relative M (M=Li, Na, K) affinities of the stabilized enolates derived from acetylacetone, ethyl acetoacetate, diethyl malonate, ethyl cyanoacetate, 2-cyanoacetamide, and methyl malonate monoamide in the gas phase. Quantum chemical calculations support the experimental results and moreover afford insight into the structures of the alkali-metal enolate complexes.

Live Monitoring of Anionic Living Polymerizations by Electrospray-Ionization Mass Spectrometry.

Anionic polymerizations are of exceptional practical importance, but difficult to analyze due to the high reactivity of the growing polymer chains. Here, we demonstrate that electrospray-ionization mass spectrometry (ESI-MS) permits direct observation of the active carbanionic intermediates formed in the anionic ring-opening polymerization of 1-cyanocyclopropanecarboxylate in tetrahydrofuran. This includes the identification of a side product, as well as real-time analysis of the polymerization reaction.

In-Situ Analysis of Anionic Coordination Polymerizations by Electrospray-Ionization Mass Spectrometry.

Anionic coordination polymerizations proceed via highly reactive intermediates, whose in situ analysis has remained difficult. Here, we show that electrospray-ionization mass spectrometry is a promising method to obtain detailed information on the polymerization process. Focusing on polymerization reactions of 1,3-dienes initiated by CoCl /RLi (R=Me, nBu, tBu, Ph), we directly observe the growing polymer chains and characterize the active anionic cobalt centers by gas-phase fragmentation experiments.

Direct Detection of Free and Counterion-Bound Carbanions by Electrospray-Ionization Mass Spectrometry.

We propose electrospray-ionization (ESI) mass spectrometry as a robust and powerful method for the in situ analysis of carbanions. ESI mass spectrometry selectively probes the charged components of the sampled solution and, thus, is ideally suited for the detection of free carbanions. We demonstrate the potential of this method by analyzing acetonitrile solutions of 15 different carbon acids AH, whose acidities cover a range of 11.