If it's ever felt like everything in your body is breaking down at once, that might not be your imagination. A new Stanford Medicine study shows that many of our molecules and microorganisms dramatically rise or fall in number ...
Aug 14, 2024
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Endometriosis is a disease in which tissue similar to what lines the uterus grows outside of it. The disease, which affects 10% of women of reproductive age worldwide, causes severe pain and often infertility. Many of the ...
Aug 14, 2024
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Indiana University School of Medicine researchers have made significant progress in understanding how cells communicate during inflammation. The study, recently published in Proceedings of the National Academy of Sciences, ...
Aug 14, 2024
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A traumatic brain injury, or TBI, is caused by a contusion to the head that may result in injury to the brain. This type of injury combined with the inherited genetic risk factors can result in the accelerated development ...
Aug 9, 2024
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Offering patients with concussion a type of brain scan known as diffusion tensor imaging MRI could help identify the one in three people who will experience persistent symptoms that can be life-changing, say Cambridge researchers.
Aug 8, 2024
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Periodontitis is initiated by dysbiosis of the oral microbiome. Pathogenic bacteria elicit ineffective immune responses, which damage surrounding tissues and lead to chronic inflammation. Although current treatments typically ...
Aug 8, 2024
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Northwestern Medicine scientists have discovered new insights into the production and regulation of a class of noncoding RNAs and how alterations in their signatures diversify and modulate the transcriptome of three major ...
Aug 5, 2024
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Injuries, infection and inflammatory diseases that damage the spinal cord can lead to intractable pain and disability. Some degree of recovery may be possible. The question is, how best to stimulate the regrowth and healing ...
Aug 2, 2024
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Standard medical procedures are often time-consuming and generally do not take into account the individual characteristics of patients. This can have a negative impact on the success of treatment and impair quality of life.
Aug 2, 2024
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Sickle cell disease, while rare, is the most common inherited blood disorder and affects over 100,000 people in the United States, more than 90% of whom are Black according to the Centers for Disease Control and Prevention. ...
Jul 31, 2024
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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.
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