For billions of years, bacteria have moved themselves using cilia. Now, researchers have constructed molecules that imitate these tiny, hair-like structures. The innovation was possible by nanofabricating artificial cilia that would respond in just one direction to provide a net displacement of motion.
In a new study, Brown Univ. neuroscientists looked cell-by-cell at the brain circuitry that tadpoles, and possibly other animals, use to avoid collisions. The study produced a model of how individual inhibitory and excitatory neurons can work together to control a simple behavior.
According to a team of researchers who applied a statistical technique to conventional, coarse-scale climate models, population centers in cool, highland regions of East Africa could be more vulnerable to malaria than previously thought, while population centers in hot, lowland areas could be less vulnerable. The new approach improves the accuracy of earlier efforts that used global climate model simulations results.
Recent computer simulations show how, for the first time, two knots on a DNA strand can interchange their positions, with one knot growing in size and the other diffusing along the contour of the first. This swapping of positions on a DNA strand may also happen in living organisms, and the mechanism may play an important role in future technologies such as nanopore sequencing.
An international collaboration of researchers have unlocked the secret behind the activation of the Ras family of proteins, one of the most important components of cellular signaling networks in biology and major drivers of cancers that are among the most difficult to treat. To make the discovery, they performed single molecule studies of Ras activation in a membrane environment.
Researchers in Sweden have headed a study that provides new knowledge about the EphA2 receptor, which is significant in several forms of cancer. The researchers employed the method of DNA origami, in which a DNA molecule is shaped into a nanostructure, and used these structures to test theories about cell signalling.
Located deep in the human gut, the small intestine is not easy to examine: X-rays, MRIs and ultrasound images each suffer limitations. Univ. at Buffalo researchers are developing a new imaging technique involving nanoparticles suspended in liquid to form “nanojuice” that patients would drink. Upon reaching the small intestine, doctors would strike the nanoparticles with laser light, providing a non-invasive, real-time view of the organ.
New research led by the Salk Institute shows, for the first time, that stem cells created using two different methods are far from identical. Their work reveals that stem cells created by moving genetic material from a skin cell into an empty egg cell, instead of activating genes to revert adult cells to their embryonic state, more closely resemble human embryonic stem cells, which are considered the gold standard in the field.
Researchers have already used molecular rotors as viscosity sensor probes in live cells, but a recent study in Singapore is the first to report on the use of fluorescent molecular rotors to study critical protein interactions.
Scientists at Scripps Institution of Oceanography have conducted the most detailed examination of green fluorescent proteins (GFPs) in lancelets, marine invertebrates also known as “amphioxus.” They have deciphered the structural components related to fluorescence and have found that only a few key structural differences at the nanoscale allows the sea creature to emit different brightness levels.
Researchers at the National Eye Institute have described the functions of a gene responsible for anchoring cilia, which are sensory hair-like extensions present on almost every cell of the body. They show in a mouse model that without the gene Cc2d2a, cilia throughout the body failed to grow, and the mice died during the embryonic stage.
In a basement laboratory at Fort Sam Houston military base in Texas, a research team has spent the last two years simulating improvised explosive device blasts on postmortem pig eyes using a high-powered shock tube. Their most striking discovery is that these blasts can damage the optic nerve, and these injuries can occur even at low pressures, causing visual defects that until now have been associated traumatic brain injuries.
Mesenchymal stem cells have become attractive tools for bioengineers, but some scientists haven’t given up on their regenerative potential. A research team at Harvard Univ. recently found that transplanting mesenchymal stem cells along with blood vessel-forming cells naturally found in circulation improves results. This co-transplantation keeps the mesenchymal stem cells alive longer in mice after engraftment, up to weeks from just hours.
Many enzymes work only with a co-trainer, of sorts. Scientists in Germany have shown what this kind of cooperation looks like in detail using a novel methodology applied to the heat shock protein Hsp90, which controls the proper folding of other proteins. Together with a second molecule, the co-chaperone P23, it splits the energy source ATP to yield the energy it needs to do its work.
Researchers have developed new methods to trace the life history of individual cells back to their origins in the fertilized egg. By looking at the copy of the human genome present in healthy cells, and by looking at the numbers and types of mutations in a cell's DNA, biologists in the U.K. have been able to build a picture of each cell's development from the early embryo on its journey to become part of an adult organ.
Using the quantitative approach of physicists, biologists in Israel have developed experimental tools to measure precisely the bacterial response to antibiotics. Their mathematical model of the process has led them to hypothesize that a daily three-hour dose would enable the bacteria to predict delivery of the drug, and go dormant for that period in order to survive.
New research suggests that scientists have only scratched the surface of understanding the nature, physiology and location of stem cells. Specifically, the report suggests that embryonic and induced pluripotent stem cells may not be the only source from which all three germ layers in the human body (nerves, liver or heart and blood vessels) can develop.
Optogenetics relies on light-sensitive proteins that can suppress or stimulate electrical signals within cells. This technique requires a light source to be implanted in the brain, where it can reach the cells to be controlled. Massachusetts Institute of Technology engineers have now developed the first light-sensitive molecule that enables neurons to be silenced noninvasively, using a light source outside the skull.
For the first time, the genome of the electric eel has been sequenced. This discovery has revealed the secret of how fishes with electric organs have evolved six times in the history of life to produce electricity outside of their bodies. This research has shed light on the genetic blueprint used to evolve these complex, novel organs.
For the first time, neuroscientists have shown they can control muscle movement by applying optogenetics, a technique that allows scientists to control neurons’ electrical impulses with light, to the spinal cords of animals that are awake and alert. Previously, scientists have used electrical stimulation or pharmacological intervention to control neurons’ activity, but these approaches were not precise enough.
The popular conception of the Neanderthal as a club-wielding carnivore is, well, rather primitive, according to a new study conducted at Massachusetts Institute of Technology. Instead, our prehistoric cousin may have had a more varied diet that, while heavy on meat, also included plant tissues, such as tubers and nuts.
Scientists working to make gene therapy a reality have solved a major hurdle: how to bypass a blood stem cell’s natural defenses and efficiently insert disease-fighting genes into the cell’s genome. In a new study, a team of researchers report that the drug rapamycin, which is commonly used to slow cancer growth, enables delivery of a therapeutic dose of genes to blood stem cells while preserving stem cell function.
Patients with persistent ringing in the ears, a condition known as tinnitus, process emotions differently in the brain from those with normal hearing, researchers report in Brain Research. Tinnitus afflicts 50 million people in the U.S., and causes those with the condition to hear noises that aren’t really there. These phantom sounds are not speech, but rather whooshing noises, train whistles, cricket noises or whines.
Rice Univ. chemical engineer Michael Wong has spent a decade amassing evidence that palladium-gold nanoparticles are excellent catalysts for cleaning polluted water, but even he was surprised at how well the particles converted biodiesel waste into valuable chemicals.
Genomic sequencing is supposed to reveal the entire genetic makeup of an organism. The technology can be used to analyze a disease-causing bacterium to determine how much harm it is capable of causing. But new research at Rockefeller Univ. suggests that current sequencing protocols overlook crucial bits of information: isolated pieces of DNA floating outside the bacterial chromosome, the core of a cell’s genetic material.