domingo, 6 de enero de 2013

Going below 0K, genomic editing, molecular motors, mechanochemistry, cellular reprogramming, and others.

ORIGINAL: SciTechDigest
SciTech #ScienceSunday Digest 1 - 
6th Jan 2013

1. Conceptualising Negative “Absolute” Temperatures.
Physicists have used finely controlled magnetic fields and lasers to force the temperature of a gas to be colder than absolute zero, i.e.minus a few billionths of a degree below zero Kelvin and This is of course intriguing, but depends crucially on the definition of temperature and entropy. The matter itself is apparently not at temperatures below zero Kelvin but rather on average the system as a whole exhibits an average temperature that can be measured as below zero - this actually depends on heating the particles up while driving their entropy down. Negative temperatures imply negative pressures and so this naturally leads to stimulating speculation on how this finding might be applied to things like dark energy, new forms of matter, repulsive gravity and mass, warping space, wormholes, and Alcubierre drives. h/t +Ninja On Rye

2. More Precise Genomic Editing.
By modifying a set of bacterial proteins that normally defend against viral invaders researchers created a system that can alter several genome sites simultaneously and can achieve much greater control over where new genes are inserted This approach can be used to disrupt a gene or replace it with a new one; the specific sequence of the RNA component allows the easy programming of a nuclease to target one or more positions in the genome. The genetic components have been deposited with a nonprofit to be made widely available to other researchers via and so we now have a cheaper, easier-to-use, more precise and accurate, widely available system that can be used to engineer a wide range of organisms for countless biotechnology and synthetic biology applications. I’ve gotten the occasional cold sore since I was a child and so would love something like this to target the HSV code buried in some cells. 

3. A Molecular Motor Rotating on an Atomic Ball Bearing.
Title says it all. Some very clever chemists created two complex individual molecules (i) a base with three legs joined to a boron and ruthenium atom, and (ii) a top with five arms joined to a five atom ring in the centre (image 2). When the 5-armed molecule was placed on the ruthenium atom a scanning tunnelling microscope was used to inject electrons into the system and controllably cause the top molecule to rotate clockwise and anticlockwise. I’m wondering whether this little molecular motor might be used as a switch (it can be moved in one-arm increments) in some form of ultra-dense mechanical computer memory or processing element? h/t +iPan Baal

4. On Progress to Superhuman Immune Systems.
In a type of study that is becoming increasingly common, researchers took mature immune cells from a patient, treated them with a known cocktail of factors to turn them into induced pluripotent stem cells, replicated / expanded the population of cells, and turned them back into the same type of cell but these new cells exhibited rejuvenated characteristics of lifespan and growth potential while retaining the ability to target cancer cells and HIV-infected cells Reason from FightAging! posits that it is surely only a matter of time before we safely imbue a person with rejuvenated populations of 2, 5, or even 10 times as many immune cells as we normally have. 

5. A Topological Recipe Book for New Materials.
Researchers showed that they can create a recipe book to build new materials using the mathematics of topology (whose properties that do not change when an object is continuously deformed) (image 1). They created a colloid by injecting tiny differently-shaped particles (that represent fundamental building-block shapes in topology) into a liquid crystal to create a novel substance that behaves somewhat like a liquid and somewhat like a solid. The new material adhered to existing mathematical topology theorems and should open the door to a range of new materials in this space. 

6. Uncovering Drug Side Effects Before Drug Trials.
A research group has created a computational / simulation tool that rapidly screens drug structures against a library of known protein structures in order to identify likely unwanted interactions and deleterious side-effects The proof-of-concept correctly predicted 969 side-effects of 658 drugs that are in widespread medical use, and also identified possible side effects for many uncharacterized experimental molecules. The new method could be helpful in uncovering serious side effects early in the development and testing of new drugs and so avoid costly investment in trials and marketing, ideally leading to cheaper medications and a quicker and improved regulatory process. 

7. Smart Drug Design Reverses Alzheimer’s Symptoms and Restores Memory Loss.
A new drug candidate derived from the regulator of a key brain enzyme called Cdk5 - overactivation of which is implicated in plaque formation - was shown to restore memory loss and reverse symptoms of Alzheimer’s disease in mice (engineered to develop the disease) when injected The mice experienced no signs of side-effects and the group is planning to conduct human trials with the hope of demonstrating the same effect in humans. The more we understand biology, the greater mechanistic insight we uncover into the workings of various molecular pathways and the structure of the molecules involved the more advances like this will be uncovered and developed: rationally designed molecular mimics or segments of natural molecules designed to plug and interfere with diseased proteins and enzymes. 

8. Mechanochemistry and Molecular Levers.
Researchers exploring stress-responsive materials discovered a particular molecular backbone that can act like a lever to open a molecular ring embedded within it when microscopic tweezers are used to grab onto two parts of the atomic chains and pull them so that they break open and react in certain spots In some cases these mechanically-induced chemical reactions occurred orders of magnitude faster than predicted. Advances like this obviously bring to mind Drexler’s nanomachanical chemical fabricators - a billion pushes and pulls per second producing a billion new molecular products. 

9. Instructing Scar Tissue to Change Itself into Healthy Tissue.
By using a cocktail of three specific genes researchers have used gene therapy to reprogram the scar tissue cells on a damaged heart into functional muscle cells, while the addition of a fourth gene stimulated the growth of blood vessels to enhance the effect So here we have a specific gene therapy, targeted to a specific population of cells (heart scar tissue) and turning these cells into more useful cells in order to repair an organ (the heart) and attain a close-to-normal healthy functioning organ. No cells, no drugs, just injected remote cellular reprogramming. 

10. Nanowire Arrays for Better Piezoelectric Energy Generators.
Researchers developed a nanogenerator consisting of an array of vertically aligned nanowires that, when deformed by an impact or twist induces a piezoelectric production of electrons The proof-of-concept work included producing enough energy to turn on an LED light, and the much more interesting case of the flick of a finger being enough to activate the nerves of a frog’s leg and cause a kick - the embedded video in the linked page is worth a watch. 

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