Sentences with phrase «of aromatic molecules»

Not exact matches

We present the discovery of benzonitrile (c - C6H5CN), one of the simplest nitrogen - bearing aromatic molecules, in the interstellar medium.

Simple aromatic molecules such as benzonitrile may be precursors for polycyclic aromatic hydrocarbon formation, providing a chemical link to the carriers of the unidentified infrared bands.

Despite their expected ubiquity, astronomical identification of specific aromatic molecules has proven elusive.

If true, this structure for C60 would be the first example of a spherical aromatic molecule.

Electron - rich aromatic molecules such as benzene can use their surplus of electrons to react with electron - poor, positively charged species, enabling benzene to exchange one of its hydrogen atoms for the electrophilic group to make a new, substituted benzene.

Oddly, however, scientists have a rough idea of what some alien molecules would smell like: many detected so far belong to a class of compounds called aromatics, which are derived from benzene (C6H6) and were originally named for their strong odors.

In the 1930s, the German theoretician Erich Hückel had claimed that certain electronic features were essential to aromatic stability; Doering and Knox set out to synthesize a group of molecules with those features.

Their particular focus was a class of molecules, called aromatic hydrocarbons, that are distinguished by their stability and restrained reactivity.

It also is the first 6 - atom aromatic ring (a hexagonal array of carbon atoms bristling with hydrogen atoms) molecule ever detected with a radio telescope.

Astronomers using the Green Bank Telescope have made the first definitive interstellar detection of benzonitrile, an intriguing organic molecule that helps to chemically link simple carbon - based molecules and truly massive ones known as polycyclic aromatic hydrocarbons.

Though benzonitrile is one of the simplest so - called aromatic molecules, it is in fact the largest molecule ever seen by radio astronomy.

NASA researchers triggered international headlines in 1996 when they discovered, among other possible indicators of life, traces of polycyclic aromatic hydrocarbons (multiringed carbon molecules found in living cells) along surface fractures in ALH84001.

Triarylmethanes are a group of compounds that derive from methane (a molecule consisting of carbon with 4 hydrogen atoms attached to it) and consist of a carbon atom center with 3 aryl (aromatic ring) groups and a hydrogen atom.

«Lignin is a complex aromatic molecule that is mainly burned to make steam in a biorefinery plant, a relatively inefficient process that doesn't create a lot of value,» says Birgitte Ahring, Ph.D., the principal investigator on the project.

The brain merges all of these inputs — photons, aromatic molecules, etc. — into our subjective experience of the object in that moment.

To improve solubility, Itami and his colleagues have developed warped nanographene molecules with chemical substituents at the outer rim of the aromatic structure.

On the basis of this information, they designed and synthesized five carbonyl - containing aromatic molecules that stay excited and emit light for up to 230 milliseconds.

It also is the first 13 - atom molecule with a 6 - atom aromatic carbon ring (a hexagonal array of carbon atoms bristling with hydrogen atoms) molecule ever detected with a radio telescope.

This 6 - atom, aromatic, ringed molecule provides a vital clue in identifying the source of a faint infrared glow permeating the Milky Way.

Some of those large molecules are like small sheets of graphite with hydrogen attached to them: we call these polycyclic aromatic hydrocarbons and they can be found in terrestrial counterparts like mothballs, for example.

Certain particle compounds may directly generate ROS in vivo because of their surface chemistry (eg, metals, organic compounds, and semiquinones) or after bioactivation by cytochrome P450 systems (eg, polycyclic aromatic hydrocarbon conversion to quinones).6, 290 a, 290 b A particle surface or anions present on otherwise more inert particles may disrupt iron homeostasis in the lung and thereby also generate ROS via Fenton reactions.291 Other PM constituents may do so indirectly by the upregulation of endogenous cellular sources (eg, nicotinamide adenine dinucleotide phosphate [NADPH]-RRB- oxidase) 292,293 or by perturbing organelle function (eg, mitochondria) by taken - up PM components.261 Particle stimulation of irritant and afferent ANS fibers may also play a role in local and systemic oxidative stress formation.294 Given the rich antioxidant defenses in the lung fluid, secondarily generated oxidization products of endogenous molecules (eg, oxidized phospholipids, proteins) or a reduction in endogenous antioxidants per se may be responsible at least in part for the state of oxidative stress in the lungs (along with instigating the subsequent cellular responses) rather than ROS derived directly from PM and its constituents.

PNNL scientists found that secondary organic aerosols formed in the presence of the toxic pollutant known as polycyclic aromatic hydrocarbons (PAHs) trapped the PAH molecules inside, shielding them from degradation.