29,152 research outputs found
Starve Cancer Cells of Glutamine: Break the Spell or Make a Hungry Monster?
Distinct from normal differentiated tissues, cancer cells reprogram nutrient uptake and utilization to accommodate their elevated demands for biosynthesis and energy production. A hallmark of these types of reprogramming is the increased utilization of, and dependency on glutamine, a nonessential amino acid, for cancer cell growth and survival. It is well-accepted that glutamine is a versatile biosynthetic substrate in cancer cells beyond its role as a proteinogenic amino acid. In addition, accumulating evidence suggests that glutamine metabolism is regulated by many factors, including tumor origin, oncogene/tumor suppressor status, epigenetic alternations and tumor microenvironment. However, despite the emerging understanding of why cancer cells depend on glutamine for growth and survival, the contribution of glutamine metabolism to tumor progression under physiological conditions is still under investigation, partially because the level of glutamine in the tumor environment is often found low. Since targeting glutamine acquisition and utilization has been proposed to be a new therapeutic strategy in cancer, it is central to understand how tumor cells respond and adapt to glutamine starvation for optimized therapeutic intervention. In this review, we first summarize the diverse usage of glutamine to support cancer cell growth and survival, and then focus our discussion on the influence of other nutrients on cancer cell adaptation to glutamine starvation as well as its implication in cancer therapy
Novel Two-dimensional Carbon Allotrope with Strong Electronic Anisotropy
Two novel two-dimensional carbon allotropes comprised of octagons and
pentagons are proposed based on the first-principles calculations. The two
carbon allotropes, named OPG-L and OPG-Z, are found to have distinct
properties. OPG-L is metallic, while OPG-Z is a gapless semimetal. Remarkably,
OPG-Z exhibits pronounced electronic anisotropy with highly anisotropic Dirac
points at the Fermi level. A tight-binding model is suggested to describe the
low-energy quasiparticles, which clarifies the origin of the anisotropic Dirac
points. Such an anisotropic electronic characteristic of OPG-Z is expected to
have wide implications in nano-electronics.Comment: 6 pages, 5 figures (accepted by Physical Review B
Probing anisotropic superfluidity of rashbons in atomic Fermi gases
Motivated by the prospect of realizing a Fermi gas of K atoms with a
synthetic non-Abelian gauge field, we investigate theoretically a strongly
interacting Fermi gas in the presence of a Rashba spin-orbit coupling. As the
two-fold spin degeneracy is lifted by spin-orbit interaction, bound pairs with
mixed singlet and triplet pairings (referred to as rashbons) emerge, leading to
an anisotropic superfluid. We show that this anisotropic superfluidity can be
probed via measuring the momentum distribution and single-particle spectral
function in a trapped atomic K cloud near a Feshbach resonance.Comment: 4 pages, 5 figure
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