scholarly journals Negative-Ion/Positive-Ion Coincidence Yields of Core-Excited Water

2016 ◽  
Vol 120 (32) ◽  
pp. 6389-6393 ◽  
Author(s):  
Christian Stråhlman ◽  
Antti Kivimäki ◽  
Robert Richter ◽  
Rami Sankari
Keyword(s):  
Negative Ion ◽  
Positive Ion

Note on radiationless transitions involving three-body collisions

1936 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
R. A. Smith
Keyword(s):  
Continuous Spectrum ◽  
Negative Ions ◽  
Bound State ◽  
Excess Energy ◽  
Negative Ion ◽  
Positive Ions ◽  
Continuous State ◽  
Direct Formation ◽  
Three Body ◽  
Positive Ion

When an electron makes a transition from a continuous state to a bound state, for example in the case of neutralization of a positive ion or formation of a negative ion, its excess energy must be disposed of in some way. It is usually given off as radiation. In the case of neutralization of positive ions the radiation forms the well-known continuous spectrum. No such spectrum due to the direct formation of negative ions has, however, been observed. This process has been fully discussed in a recent paper by Massey and Smith. It is shown that in this case the spectrum would be difficult to observe.

Serum Lipids Profiling Perturbances in Patients with Ischemic Heart Disease and Ischemic Cardiomyopathy

2020 ◽  
Author(s):  
Lin Yang ◽  
Liang Wang ◽  
Yangyang Deng ◽  
Lizhe Sun ◽  
Bowen Low ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ischemic Heart Disease ◽  
Ischemic Cardiomyopathy ◽  
Serum Lipids ◽  
Ischemic Heart ◽  
Negative Ion ◽  
Serum Samples ◽  
Cross Sectional ◽  
Negative Ion Mode ◽  
Positive Ion

Abstract Background: Ischemic heart disease (IHD) is a common cardiovascular disorder associated with inadequate blood supply to the myocardium. Chronic coronary ischemia leads to ischemic cardiomyopathy (ICM). Despite their rising prevalence and morbidity, few studies have discussed the lipids alterations in these patients. Methods: In this cross-sectional study, we analyzed serum lipids profile in IHD and ICM patients using a lipidomics approach. Consecutive consenting patients admitted to the hospital for IHD and ICM were enrolled. Serum samples were obtained after overnight fasting. Non-targeted metabolomics was applied to demonstrate lipids metabolic profile in control, IHD and ICM patients. Results: A total of 63 and 62 lipids were detected in negative and positive ion mode respectively. Among them, 16:0 Lyso PI, 18:1 Lyso PI in negative ion mode, and 19:0 Lyso PC, 12:0 SM d18:1/12:0, 15:0 Lyso PC, 17:0 PC, 18:1-18:0 PC in positive ion mode were significantly altered both in IHD and ICM as compared to control. 13:0 Lyso PI, 18:0 Lyso PI, 16:0 PE, 14:0 PC DMPC, 16:0 ceramide, 18:0 ceramide in negative ion mode, and 17:0 PE, 19:0 PC, 14:0 Lyso PC, 20:0 Lyso PC, 18:0 PC DSPC, 18:0-22:6 PC in positive ion mode were significantly altered only in ICM as compared to IHD and control. Conclusion: Using non-targeted lipidomics profiling, we have successfully identified a group of circulating lipids that were significantly altered in IHD and ICM. The lipids metabolic signatures shed light on potential new biomarkers and therapeutics for preventing and treating ICM.

THE ELECTRON SPIN RESONANCE SPECTRA OF THE POSITIVE AND NEGATIVE IONS OF DIPHENYLENE

1960 ◽  
Vol 38 (4) ◽  
pp. 503-507 ◽  
Author(s):  
C. A. McDowell ◽  
J. R. Rowlands
Keyword(s):  
Electron Spin Resonance ◽  
Hyperfine Interaction ◽  
Electron Spin ◽  
Negative Ions ◽  
Negative Ion ◽  
Spin Resonance ◽  
Hyperfine Splittings ◽  
Positive Ion

The electron spin resonance spectra of the positive and negative ions of diphenylene have been measured. It has been found that these spectra consist of five lines showing that the observed hyperfine interaction is caused by four equivalent protons. The over-all extent of the positive ion spectrum is 18 gauss compared with that of 12.9 gauss for the negative ion. The hyperfine splittings observed are 4.0 gauss and 2.75 gauss respectively.

Core-level positive-ion and negative-ion fragmentation of gaseous and condensed HCCl3 using synchrotron radiation

2011 ◽  
Vol 135 (4) ◽  
pp. 044303 ◽  
Author(s):  
K. T. Lu ◽  
J. M. Chen ◽  
J. M. Lee ◽  
S. C. Haw ◽  
Y. C. Liang ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Core Level ◽  
Negative Ion ◽  
Ion Fragmentation ◽  
Positive Ion

Structural investigation of perfluorocarboxylic acid derivatives formed in the reaction with N,N-dimethylformamide dialkylacetals

2019 ◽  
Vol 26 (2) ◽  
pp. 131-143 ◽  
Author(s):  
Monika Stróżyńska ◽  
Jürgen H. Gross ◽  
Katrin Schuhen
Keyword(s):  
Structural Investigation ◽  
Direct Analysis ◽  
Dimethyl Acetal ◽  
Negative Ion ◽  
Cluster Ions ◽  
Perfluorocarboxylic Acid ◽  
Reaction Products ◽  
Salt Structure ◽  
Negative Ion Mode ◽  
Positive Ion

A structural investigation of perfluorocarboxylic acid derivatives formed in the reaction with N,N-dimethylformamide dialkylacetals employing several techniques of mass spectrometry (MS) is described. Two derivatizing reagents, dimethylformamide dimethyl acetal (DMF-DMA) and dimethylformamide diethylacetal (DMF-DEA) were used. In contrast to carboxylic acids, perfluorocarboxylic acids are not able to form alkyl esters as the main product in this reaction. We found that perfluorooctanoic acid (PFOA) forms a salt with N,N-dimethylformamide dialkylacetals. This salt undergoes a further reaction inside the injection block of a gas chromatograph (GC) by loss of CO2 and then forms 1,1-perfluorooctane-(N,N,N,N-tetramethyl)-diamine. The GC-MS experiments using both electron ionization (EI) and positive-ion chemical ionization (PCI) revealed that the same reaction products are formed with either derivatizing reagent. Subjecting the perfluorocarboxylic acid derivative to electrospray ionization (ESI) and direct analysis in real time (DART), both positive- and negative-ion modes indicated that cluster ions are formed. In the positive-ion mode, this cluster ion consists of two iminium cations and one PFOA anion, while in the negative-ion mode, it comprises two PFOA anions and one cation. The salt structure was further confirmed by liquid injection field desorption/ionization (LIFDI) as well as infrared (IR) spectroscopy. We propose a simple mechanism of N,N,N′,N′-tetramethylformamidinium cation formation. The structure elucidation is supported by specific fragment ions as obtained by GC-EI-MS and GC-PCI-MS analyses.

Negative Ion Mass Spectra of Organic Nitriles

1981 ◽  
Vol 35 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Kenneth L. Bush ◽  
Carol E. Parker ◽  
Donald J. Harvan ◽  
Maurice M. Bursey ◽  
J. Ronald Hass
Keyword(s):  
Mass Spectra ◽  
Chemical Ionization ◽  
Detection Limits ◽  
Negative Ion ◽  
Ionization Source ◽  
Ion Molecule Reactions ◽  
Residual Oxygen ◽  
Chemical Ionization Source ◽  
Positive Ion

Negative ion mass spectra organic nitriles have been determined using 1 Torr of methane moderator/reagent gas in a chemical ionization source. The spectra contain abundant (M – 1)− ions, and fragmentations are minimal. Ion/molecule reactions with residual oxygen, methane, and between sample molecules and ions form diverse products with low abundances relative to the ( M – 1)−. Detection limits are comparable with positive ion methods, and for selected compounds, can be several orders of magnitude lower.

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