News tagged with molecules
Scientists identify molecular trigger for Alzheimer's disease
Researchers have pinpointed a catalytic trigger for the onset of Alzheimer's disease – when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons ...
Alzheimer's disease & dementia
9 hours ago |
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Heroin vaccine blocks relapse in preclinical study
Scientists at The Scripps Research Institute (TSRI) have reported successful preclinical tests of a new vaccine against heroin. The vaccine targets heroin and its psychoactive breakdown products in the bloodstream, preventing ...
Medical research
May 06, 2013 |
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Team finds dissimilar proteins evolved similar 7-part shape
Solving the structure of a critical human molecule involved in cancer, scientists at The Scripps Research Institute (TSRI) have found what they call a good example of structural conservation—dissimilar ...
Medical research
May 01, 2013 |
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Making a window for drug delivery in the blood-brain barrier
(Medical Xpress)—The blood-brain barrier (BBB) prevents most large or hydrophilic (polar) molecules from getting into the brain. For many neurological diseases, like Parkinson's, the presence of the BBB ...
Medical research
Apr 30, 2013 |
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Missing link in Parkinson's disease found
Researchers at Washington University School of Medicine in St. Louis have described a missing link in understanding how damage to the body's cellular power plants leads to Parkinson's disease and, perhaps ...
Medical research
Apr 25, 2013 |
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Are human genes patentable?
(Medical Xpress)—On April 15, the Supreme Court will hear oral argument in Association for Molecular Pathology v. Myriad Genetics, a case that could answer the question, "Under what conditions, if any, ...
Genetics
Apr 11, 2013 |
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Signature of circulating breast tumor cells that spread to the brain found
Some breast tumor circulating cells in the bloodstream are marked by a constellation of biomarkers that identify them as those destined to seed the brain with a deadly spread of cancer, said researchers led by those at Baylor ...
Cancer
Apr 10, 2013 |
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Key pathway to stop dangerous, out-of-control inflammation discovered
A potential new strategy to developing new drugs to control inflammation without serious side effects has been found by Georgia State University researchers and international colleagues.
Inflammatory disorders
Apr 09, 2013 |
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Will cell therapy become a 'third pillar' of medicine?
Treating patients with cells may one day become as common as it is now to treat the sick with drugs made from engineered proteins, antibodies or smaller chemicals, according to UC San Francisco researchers. They outlined ...
Medical research
Apr 03, 2013 |
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New discovery could lead to powerful new anti-malaria drugs
An international study has discovered a molecule which could form the basis of powerful new anti-malaria drugs. The paper "Quinolone-3-Diarylethers: a new class of drugs for a new era of malaria eradication" has been published ...
Medical research
Mar 20, 2013 |
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Green tea extract interferes with the formation of amyloid plaques in Alzheimer's disease
(Medical Xpress)—Researchers at the University of Michigan have found a new potential benefit of a molecule in green tea: preventing the misfolding of specific proteins in the brain.
Alzheimer's disease & dementia
Mar 05, 2013 |
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Study shows how insulin-like molecules play critical role in learning and memory
Though it's most often associated with disorders like diabetes, Harvard researchers have shown how the signaling pathway of insulin and insulin-like peptides plays another critical role in the body – helping ...
Neuroscience
Feb 26, 2013 |
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New study refutes accepted model of memory formation
A study by Johns Hopkins researchers has shown that a widely accepted model of long-term memory formation—that it hinges on a single enzyme in the brain—is flawed. The new study, published in the Jan. 2 issue of Nature, found ...
Neuroscience
Jan 02, 2013 |
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Researchers uncover toxic interaction in neurons that leads to dementia and ALS
Researchers at Mayo Clinic in Florida have uncovered a toxic cellular process by which a protein that maintains the health of neurons becomes deficient and can lead to dementia. The findings shed new light on the link between ...
Medical research
Dec 10, 2012 |
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New understanding of how we see colors
(Medical Xpress)—Scientists have until now not fully understood how animals see in color, since visual pigments in eyes contain exactly the same chromophore (light absorbing segment of the molecule) and yet can absorb different ...
Medical research
Dec 07, 2012 |
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Molecule
A molecule is defined as a sufficiently stable, electrically neutral group of at least two atoms in a definite arrangement held together by very strong (covalent) chemical bonds. Molecules are distinguished from polyatomic ions in this strict sense. In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and biomolecules.
In the kinetic theory of gases the term molecule is often used for any gaseous particle regardless of its composition. According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.
A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules.
No typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding. In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without any definable molecule, but also without any of the regularity of repeating units that characterises crystals.
For more information about Molecule, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
