Permalink here: http://www.scitechdigest.net/2015/09/dna-origami-polymers-sonogenetic.html
DNA origami polymers, Sonogenetic neurons, Transparent brains, Prosthetics sense touch, Hacking neurons, Microfluidic RAM, Kirigami 3D fabrication, Algorithmic language parsing, Graphene filament, Tunable cheap catalysts.
1. Precisely Assembled Polymers from DNA Origami
Self assembled DNA origami technology has now been used to controllably form precisely ordered arrangements of conductive polymers in two and three dimensions http://phys.org/news/2015-09-sculpting-conjugated-polymer-dna-origami.html. This was enabled by functionalising a conjugated polymer with a specific sequence of single-stranded DNA; when the polymer is then added in solution to a surface on which a DNA origami array has already been formed the polymer strands can be made to form specific shapes and structures as desired, and because the polymer remains conductive this suggests the technique might be used for molecular circuit design.
2. Sonogenetics to Control Neurons with Sound
In a similar way to how optogenetics uses neurons genetically altered with light-sensitive proteins to make them respond to light, the new field of sonogenetics uses a different ion channel protein that is sensitive to focused pulses of ultrasound to make genetically altered neurons respond to ultrasound http://neurosciencenews.com/sonogenetics-neuroscience-neurons-2640/. The embedded video shows a nematode worm being made to switch direction when ultrasound is switched on, also showing the genetically-altered neurons responsible firing up in response. Ultrasound can pass through tissues and structures that light can and so the technique might be less or non-invasive compared to optogenetics. Although optogenetics got a boost this week too http://www.ibs.re.kr/cop/bbs/BBSMSTR_000000000738/selectBoardArticle.do?nttId=12028.
3. Creating Better Transparent Brains
A new technique provides a better method for turning brains transparent in order to better image 3D brain anatomy at high resolution http://www.kurzweilai.net/changing-behavior-with-synapse-engineering. Called ScaleS, the technique is an improvement on other methods that results in minimal tissue damage, uses a mixture of sorbitol and urea, is compatible with labelling techniques, and preserves tissue integrity able to withstand micron-slicing and electron microscopy. As a proof of concept the team used the tool to derive new insights into the location of Alzheimers plaques and different specialised brain cells.
4. DARPA’s Prosthetics Sense Touch
A new advance from DARPA in prosthetics and brain-computer-interfaces has resulted in the first genuine prosthetic control + sensation closed-loop system http://www.darpa.mil/news-events/2015-09-11. The prosthetic arm attached to a 28 year old volunteer incorporated both electrode implanted into (i) the motor cortex to read brain signals and move the arm and hand, and (ii) the relevant area of the sensory cortex to input signals from sensitive touch sensors on the fingers of the prosthetic arm. In blind tests the person successfully reported which finger was touched and even knew when the researchers tried to trick them; they reported that it felt as though someone was touching their real hand.
5. Hacking Neurons
First, a study in rats with spinal cord injuries demonstrates that synchronising attempted muscle movement with neural stimulation - via a Neurochip-2 device in this case - provides a measureable and significant boost to neuroplasticity that resulted in the ability to perform a learned task twice as well without the stimulation, if not quite as well before the injury http://spectrum.ieee.org/tech-talk/biomedical/bionics/stimulating-damaged-spines-rewires-rats-for-recovery. Second, a group engineered the synaptic weights - from inhibitory to excitatory - on a single neuron in a nematode worm and was able to alter its behaviour to swim towards rather than away from a threat, and was able to do this by swapping out different ion channels in the live nematode http://www.umassmed.edu/news/news-archives/2015/09/changing-behavior-through-synaptic-engineering/.
6. Storing Cells in Random Access Memory
Microfluidic circuits can now be formed into architectures that enable the functional equivalent of transistors that store and shuttle living cells instead of electrons http://phys.org/news/2015-09-random-access-memory-cells.html. The group created a random access memory equivalent for living cells, exerting far finer control over switching states than had ever previously been achieved, and they hope to be able to create large single-cell memories in future. The ultimate goal for tools like this is to swiftly sort through a great many cells to find rare cells that may be indicative of certain diseases or disorders.
7. Novel 3D Fabrication Techniques with Kirigami
First, complex and closed “pop-up” 3D structures can now be formed based on Japanese Kirigami techniques after forming 2D structures with strategically-placed cuts made by conventional semiconductor fabrication methods http://www.northwestern.edu/newscenter/stories/2015/09/3d-fabrication.html. Fundamentally this represents a new set of design rules for transforming most 2D electronics and photonics surfaces into complex 3D shapes. Second, again taking inspiration from Japanese Kirigami techniques, new 2D solar panels with strategic cuts are able to bend and flex in three dimensions to quickly alter the orientation of the solar cell’s surface towards the sun for improved efficiency http://ns.umich.edu/new/multimedia/videos/23109-inspired-by-art-lightweight-solar-cells-track-the-sun.
8. Better Machine Learning Language Parsing
A new machine-learning system can distinguish not just words but lower-level units in language such as phonemes and syllables http://news.mit.edu/2015/learning-spoken-language-phoneme-data-0914. Unlike other comparable systems this one is unsupervised and doesn’t rely on human expert annotations, and it should enable better handling of rare languages and more accurate determination between different accents or pronunciations. Interesting assumptions built into the system include its use of a noisy channel and that word frequency will follow a power-law distribution, a phenomenon that was covered wonderfully by Vsauce recently https://www.youtube.com/watch?v=fCn8zs912OE.
9. 3D Printing Graphene Filament and Nerve Guides
First, a new start-up company Graphene 3D Lab has launched a graphene-based conductive polymer filament for use in 3D printers and which can help produce conductive components and electronic devices (a battery was produced as a demonstration product) and the material claims a conductivity 25 times better than comparable filaments http://spectrum.ieee.org/nanoclast/semiconductors/materials/graphene-filament-enables-fabrication-of-electronic-devices-with-3d-printing. Second, 3D printed silicone structures loaded with specific biochemical growth promoters act as personalised nerve growth guides to help restore nerve function and movement after damage and was successfully tested in rats http://phys.org/news/2015-09-d-regrow-complex-nerves-injury.html.
10. Tuning Cheap Catalysts for Different Reactions
A new multi-purpose catalyst platform is based on cheap graphite, the edges of which are functionalised by binding different compounds whose composition and quantity generate a specific catalytic framework able to accelerate specific reactions http://news.mit.edu/2015/inexpensive-new-catalysts-fine-tuned-0916. The approach combines both heterogeneous and molecular electrocatalysts and ultimately aims to replace expensive catalysts across a range of different industrial chemical processes including fuel cells, carbon capture, and compound synthesis. The basic materials and processes exploit materials and systems that are already employed at industrial scale, which should facilitate scale-up.