A quantum dot is a nanometric crystalline structure of semiconductor materials. In a quatum dot electrons are confined in a region of space, thus creating a well defined structure of energy levels that depends very much on the size and shape of the quantum dot. This structure resembles that of atoms, that is why sometimes […]
The immune system is a complex network that recognises foreign substances in the body. When it detects an alien substance (antigen), it creates antibodies to attack and destroy it. This system protects vertebrates against viruses, bacteria, fungi and other parasites, and is the reason for the “rejection” after organ transplants. When we have cancer, our […]
The ability to trap and control particles with the help of well-controlled electromagnetic fields has led to revolutionary advances in the fields of biology, condensed- matter physics, high-precision spectroscopy, and quantum information, enabling unprecedented control both in the study of isolated single particles as well as in few and many-body systems subject to controlled and […]
W orld Health Organization (WHO) established the recognition of obesity as a disease in 1948, but it was not until the last decade of the 20th century that people began to gain awareness of overweight-derived health problems. A decade ago and based on worldwide data indicating that 40 % of global adult population were overweight […]
A dielectric is a nonconductor of electric charge in which an applied electric field causes a displacement of charge but not a flow of charge. Light propagation through a dielectric medium is determined by the spatial distribution of the material. Photons scatter at local variations of the refractive index. Therefore, how ordered the medium is […]
Collagen is the newest trendy nutrient. If we search for “collagen” in the web browser, we will find a wide variety of food supplements, cosmetic products and web pages where collagen beneficial effects are highlighted. Although collagen is a mere protein, its name is currently associated to the wellness circuit and, for this reason, it […]
A placebo is a substance or treatment that does not contain any active ingredient or rest in a physiological procedure out of the placebo effect, but still achieves a real change. The placebo effect is a psychobiological phenomenon, but it generates authentic physical changes, something that can be observed, for example, in the heartbeat, blood […]
Electrons do not move around nuclei in defined curved orbits. Our current understanding of how electrons are to be found in atoms and molecules is based on clouds of probability called orbitals as it is not possible to give a definite path for an electron. Thus, an orbital is a region in which an electron […]
Thomas C. Südhof (Göttingen, Germany, December 22, 1955) is a neurobiologist awarded in 2013 with the Nobel Prize in Medicine for his studies on the trafficking of vesicles in the cell. Südhof has just published an article in the journal Cell, one of the best in the world, about neurexins, one of the most interesting […]
When light encounters molecules, the predominant mode of scattering is elastic scattering (Rayleigh). This scattering is responsible for the blue colour of the sky, for example. It is also possible for the incident photons to interact with the molecules in such a way that energy is either gained or lost so that the scattered photons […]