Sentences with phrase «by molecules known»

Not exact matches

More amazingly, we now know that beneath the crust of Enceladus is a global ocean of liquid saltwater and organic molecules, all being heated by hydrothermal vents on the seafloor.

It is now well known that vast amounts of water and over 120 molecules, including complex organic molecules, are found in interstellar space, having been created by stars and nebulae (the Orion Nebula alone churns out huge amounts of water).

By abstraction, we can account for certain types of events, but we can no more predict the particular event than a chemist can predict the location of a single molecule in a gas - filled chamber.

Mutations are indeed not, so far as we know, selected by any overall purpose favoring evolution; but this is compatible with there being short - run and very naive purposes, desires, or feelings in the atoms and molecules constituting the genes, as well as in every cell and every metazoan with a nervous system.

... The direct synthesis of... nucleotides from prebiotic precursors in reasonable yield and unaccompanied by larger amounts of unrelated molecules could not be achieved by presently known chemical reactions» (5).

That approach — known as electrospray ionization — ionizes large molecules by dissolving them in a solvent and using an intense electric field to pull tiny charged droplets of solution from the end of a needle.

A class of small molecules found in grapes, red wine, olive oil, and other foods extends the life of yeast cells by approximately 70 % and activates genes known to extend life span in laboratory animals.

Next, the team tested chemicals they suspected would react with the smelly molecules to produce larger molecules that could no longer be smelled, or a different shape that would be perceived differently by the nose.

To address this, scientists at Stanford University in Palo Alto, California, led by chemist Jianghong Rao, have taken advantage of a naturally produced TB protein known as BlaC to create an efficient detection method that uses a simple fluorescent molecule.

3BP, part of a class of compounds known as small molecule drugs, was first studied as an anti-cancer agent more than a decade ago at Johns Hopkins by biochemists Young Hee Ko and Peter Pedersen, together with radiologist Jeff Geschwind.

The rays do this by causing molecules in the ring known as amide groups to shuffle from opposite sides of the carbon bond to the same side, loosening hydrogen bonds in the process.

Ten years later, no one knows what was in the cloud of gases released by the combustion of all that jet fuel and building material but science has revealed what was in the dust — cement, steel, gypsum from drywall, building materials, cellulose from paper, synthetic molecules from rugs, glass fibers and human hair from the long decades of the two towers» use, among other items.

Tritium, another harmful radionuclide, can not be safely removed by any known purification system because it is incorporated within water molecules.

According to Zhang, the branching structure of the ligands protects the surface of the nanocrystals by occupying more space than straight - chain molecules, creating a mechanical barrier through an effect known as steric hindrance.

Luckily, the same exact molecule is more inexpensively created from natural gas by a few obscure Chinese chemical companies and a well - known German multinational corporation.

At a certain ratio of cerium atoms to molecules, self - assembly produced a symmetrical complex 2 - D pattern described originally by Kepler and known today as the snub square tiling.

These agents are called disaccharide derivatives, and they mimic a class of natural molecules known as rhamnolipids, which are produced and secreted by the bacterium itself.

But the flowers that Gaskett studies, called tongue orchids, can produce a molecule that precisely mimics the pheromone made by the females of the species Lissopimpla excelsa, commonly known as dupe wasps.

The activity of the latter protein is known to be blocked by a small molecule called Nutlin - 3.

What industrial chemists did know was that by tinkering with a highly reactive molecule called a phenol they were able to devise countless synthetic chemicals for use in new materials.

Because nitric oxide breaks down very quickly, as soon as the chemical is no longer being produced, the oxygen molecules are again trapped by the mitochondria and are not available for the production of light.

The ER / PR receptors also have no known direct connection to the signaling molecules activated by MC1R.

Vtesse is currently running a late - stage clinical trial of the drug, a large sugar molecule known as a cyclodextrin, in which it is injected by lumbar puncture into the spinal fluid of children with the disease (see «Why are people fighting over a promising treatment for a fatal childhood disease»).

When prion protein molecules are sequestered by their misfolded counterparts, they can no longer work as a scaffold for all these molecular interactions, which impairs the mechanisms evoked by the brain chemicals important for mood.

For example, their surface is covered by glycoconjugates that are essential for their survival and infectivity, but little is known of the processes that lead to the synthesis of such molecules.

If we know, for example, that a cancer cell can be killed by deactivating a certain enzyme, researchers can build a detailed, 3 - D computer model of the enzyme to look for molecules that can go in and disable it.

The tool, known as DESI mass spectrometry imaging (or Desorption ElectroSpray Ionization mass spectrometry imaging), works by turning molecules into electrically charged versions of themselves, called ions, so that they can be identified by their mass.

The sulphur - containing molecule methyl mercaptan is naturally produced in significant quantities on Earth only by microbes, including some that make their pungent presence known in the human body.

The Fem RNA breaks down a corresponding molecule made by a gene known as Masculinizer, which is found on the Z chromosome.

This sensitivity was reversed by an antibody known to neutralise the molecule.

Prior to the current study, the scientists already knew that Rumi modifies Notch by adding glucose molecules to the protein.

Snippets of RNA known as short interfering RNA (siRNA) turn off specific genes inside living cells by destroying the messenger RNA molecules that carry DNA's instructions to the rest of the cell.

But the nature of these dimers has been hotly debated because it was not known whether the two beta - amyloid molecules that form the dimer were linked by a chemical bond or not.

Gleevec incapacitates the enzyme by docking into a pocket on the enzyme's surface that is usually reserved for a signaling molecule known as ATP.

The science team, led by chemist Brett McGuire at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, detected this molecule's telltale radio signature coming from a nearby star - forming nebula known as the Taurus Molecular Cloud 1 (TCM - 1), which is about 430 light - years from Earth.

When the scientists blocked Treg cells from accumulating in the fat by targeting a molecule that the immune cells require, mice no longer developed type 4 diabetes in old age.

A proposed pathway to construct quantum computers may be the outcome of research by a University of Oklahoma physics team that has created a new molecule based on the interaction between a highly - excited type of atom known as a Rydberg atom and a ground - state atom.

To explore the health consequences of quorum sensing in the crypts, the researchers introduced into the flow a molecule that acts as an antagonist to turn off quorum sensing in chambers colonized by the well - known scourge of hospitals, methicillin - resistant S. aureus, or MRSA.

The researchers began by creating large membrane models with embedded and dyed channel proteins; they then put them on a glass surface and measured them using a single - molecule measuring method known as fluorescence correlation spectroscopy.

Researchers at UT Southwestern Medical Center have found a new way that internal body clocks are regulated by a type of molecule known as long non-coding RNA.

The scientists did this by manipulating a small molecule known as sphingosine -1-phosphate (S1P), which they report is found in elevated levels in people with sickle cell disease.

Makoto Fujita and his team from Japan's University of Tokyo created scaffolding - like crystalline structures known as metal - organic frameworks, or MOFs, whose empty spaces can soak up molecules and provide an ordered array that enables the molecules to then be characterized by X-ray analysis.

Led by reproductive biologist Alex Travis, the engineering effort focuses on a chain of enzymes that metabolize glucose molecules into the biological fuel ATP (a process known as glycolysis), which enables sperm locomotion.

In past work studying strains of E. coli known to cause difficult - to - treat UTIs, the researchers showed that a molecule called yersiniabactin that is secreted by the bacteria sequesters copper, preventing it from accumulating to antibacterial levels.

«This experiment would be the first to look for life by targeting the molecules specific to life as we know it,» says Christopher Carr, the lead engineer on the project.

«To reach their target, growing axons rely on molecules known as guidance cues, which instruct them on which direction to take by repelling or attracting them to their destination,» explains Dr. Charron, Director of the Molecular Biology of Neural Development research unit at the IRCM.

The findings suggest that the molecule — known as an antisense oligonucleotide — potentially could treat neurodegenerative diseases characterized by abnormal tau, including Alzheimer's.

They found that these skin - resident immune cells function as «first responders» to skin injuries in part by producing the molecule known as interleukin - 17A (IL - 17A), which wards off infection and promotes wound healing.

«We may not even know what we should be looking for in these asteroids, but by looking at what molecules we find, we can ask different and more questions about how they could have helped get life started.»

Selective imaging by correlated optical and electron microscopy of protein molecules of known ages will clarify fundamental processes of protein trafficking in situ.