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We report on the production and study of stable, highly charged droplets of superfluid helium. Using a novel experimental setup we produce neutral beams of liquid helium nanodroplets containing millions of atoms or more that can be ionized by electron impact, mass-per-charge selected, and ionized a second time before being analyzed. Droplets containing up to 55 net positive charges are identified and the appearance sizes of multiply charge droplets are determined as a function of the charge state. We show that the droplets are stable on the millisecond timescale of the experiment and decay through the loss of small charged clusters, not through symmetric Coulomb explosions.
This article was published in the following journal.
Name: Physical review letters
Helium is recognized as a model system for the study of phase transitions. Of particular interest is the superfluid phase in two dimensions. We report measurements on superfluid helium films adsorbed ...
The 0.4 K internal temperature of superfluid helium nanodroplets is believed to guarantee a corresponding ground state population of dopant atoms and molecules inside this cryogenic matrix. We have re...
We report high-resolution infrared spectroscopic studies on complexes of propargyl alcohol with water (D2O) molecules, formed in superfluid helium droplets. The spectra were recorded in the frequency ...
The dynamics of the Ne2 dimer and Ne-Ne adduct formation in a superfluid helium nanodroplet [(4He)N; T = 0.37 K], Ne + Ne@(4He)N → Ne2@(4He)N'/Ne-Ne@(4He)N' + (N-N')4He with N = 500, has been invest...
In contrast to conventional dispersions of solid microspheres, dilute dispersions containing soft hydrogel microspheres (microgels) exhibit unique drying behavior due to their selective adsorption at ...
The main purpose of this study is to assess and test the reproducibility and results of hyperpolarized 3-Helium gas as a contrast agent with Magnetic Resonance Imaging (MRI) of the lungs i...
The purpose of this study is to compare the changes in blood lipids and feelings of satiety after consumption of acid stable or acid unstable oil-in-water emulsions in which the droplets a...
The goal of this research is to use Helium-3 MRI to see the changes in airflow of the lungs at different times of an attack. These three stages are immediately after the attack, 1 month la...
The purpose of this study is to compare the changes in blood lipids and feelings of satiety after consumption of oil-in-water emulsions in which the droplets are in either the liquid or so...
Helium—oxygen mixture(heliox) was suggested to be beneficial in meconium aspiration syndrome in previous studies，but the evidence was limited．The aim of the study was to assess the e...
A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
Positively-charged atomic nuclei that have been stripped of their electrons. These particles have one or more units of electric charge and a mass exceeding that of the Helium-4 nucleus (alpha particle).
A perilipin that is expressed by many different cell types. It binds FATTY ACIDS and CHOLESTEROL, stabilizes TRIGLYCERIDES, and localizes to both the surface and hydrophobic core of LIPID DROPLETS, as well as the ENDOPLASMIC RECTICULUM and PLASMA MEMBRANE in MACROPHAGES. It also plays a central role in the biogenesis of lipid droplets and FOAM CELLS and is highly expressed by macrophages at atherosclerotic lesions in human arteries along with the INFLAMMATION markers TNF-ALPHA; MCP-1 RECEPTOR; and IL-6.
Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.
Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)