For the past seven years or so, electric vehicles have been on the rise. Tesla is practically a household name, and it’s not uncommon to see EVs from companies like Nissan, Chevy, and BMW on the road now. That wouldn’t have happened without the lithium ion battery. Right now, lithium ion is the most popular battery type for electric vehicles. It can last up to 200 miles on a single charge, and it’s not too expensive to make, which means EVs are also relatively affordable.
But experts say that lithium ion batteries can only take electric cars so far—both on the road and in the marketplace. Before they can beat more popular combustion engine cars, electric vehicles will need a battery makeover, which is why countless engineers and scientists are searching for the next EV battery.
So what’s it going to look like? There are dozens of battery chemistries to play with. But how many of them can even approach the success of lithium ion? Electric vehicle advocate and blogger Chelsea Sexton joins George Crabtree, the director of the Joint Center for Energy Storage Research at Argonne National Laboratory, to discuss potential successors to the popular lithium ion battery.
Scientists from Singapore have streamlined the process of using human stem cells to mass produce GABAergic neurons (GNs) in the laboratory. This new protocol provides scientists with a robust source of GNs to study many psychiatric and neurological disorders such as autism, schizophrenia, and epilepsy, which are thought to develop at least in part due to GN dysfunction.
GNs are inhibitory neurons that reduce neuronal activation, and make up roughly 20 per cent of the human brain. They work alongside excitatory neurons (ENs) to ensure balanced neural activity for normal brain function. The coordinated interplay between GNs and ENs orchestrate specific activation patterns in the brain, which are responsible for our behaviour, emotions, and higher reasoning. Functional impairment of GNs results in imbalanced neural activity, thereby contributing to the symptoms observed in many psychiatric disorders.
The availability of high quality, functional human GN populations would facilitate the development of good models for studying psychiatric disorders, as well as for screening drug effects on specific populations of neurons. Scientists worldwide have been hard at work trying to generate a consistent supply of GNs in the laboratory, but have been faced with many challenges. Protocols involving multiple complex stages, poor yield, and requiring a long time to generate mature and functional GNs are just some of the limitations encountered.
Many of these limitations have now been overcome by the development of a rapid and robust protocol to generate GNs from human pluripotent stem cells (hPSCs) in a single step. With the addition of a specific combination of factors, hPSCs turn into mature and functional GNs in a mere six – eight weeks. This is about two – three times faster than the 10 - 30 weeks required for previous protocols. In addition, this new protocol is highly efficient, with GNs making up more than 80 per cent of the final neuron population.
To develop this protocol, the team from Duke-NUS Medical School (Duke-NUS), A*STAR’s Genome Institute of Singapore (GIS) and the National Neuroscience Institute (NNI) first identified genetic factors involved in GN development in the brain. The team then tried many different combinations of these factors, and succeeded in confirming that mature and functional human GNs were indeed generated.
“Just like how a balance of Yin and Yang is needed in order to stay healthy, a balance of ENs and GNs is required for normal brain function. We now know a fair bit about ENs because we have good protocols to make them. However, we still know very little of the other player, the GNs, because current protocols do not work well. Yet, when these GNs malfunction our brain goes haywire,” commented Dr Alfred Sun, a Research Fellow at NNI and co-first author of the publication alongside Mr Qiang Yuan, an NUS Graduate School PhD student.
“Our quick, efficient and easy way to mass produce GNs for lab use is a game changer for neuroscience and drug discovery. With increased recognition of the essential role of GNs in almost all neurological and psychiatric diseases, we envisage our new method to be widely used to advance research and drug screening,” said Dr Shawn Je, Assistant Professor in the Neuroscience and Behavioural Disorders Programme at Duke-NUS, and senior author of the study.
The speed and efficiency of generating GNs with this new protocol provides researchers unprecedented access to the quantities of neurons necessary for studying the role of GNs in disease mechanisms. Drugs and small molecules may now be screened at an unparalleled rate to discover the next blockbuster treatment for autism, schizophrenia, and epilepsy.
Friday, Oct. 20, NASA astronauts Randy Bresnik and Joe Acaba ventured outside the International Space Station for a 6 hour and 49 minute spacewalk. Just like you make improvements to your home on Earth, astronauts living in space periodically go outside the space station to make updates on their orbiting home.
All spacewalks begin inside the space station. Astronauts Paolo Nespoli and Mark Vande Hei helped each spacewalker put on their suit, known as an Extravehicular Mobility Unit (EMU).
They then enter an airlock and regulate the pressure so that they can enter the vacuum of space safely. If they did not regulate the pressure safely, the astronauts could experience something referred to as “the bends” – similar to scuba divers.
Once the two astronauts exited the airlock and were outside the space station, they went to their respective work stations.
Bresnik replaced a failed fuse on the end of the Dextre robotic arm extension, which helps capture visiting vehicles.
During that time, Acaba set up a portable foot restraint to help him get in the right position to install a new camera.
While he was getting set up, he realized that there was unexpected wearing on one of his safety tethers. Astronauts have multiple safety mechanisms for spacewalking, including a “jet pack” on their spacesuit. That way, in the unlikely instance they become untethered from the station, the are able to propel back to safety.
Bresnik was a great teammate and brought Acaba a spare safety tether to use.
Once Acaba secured himself in the foot restraint that was attached to the end of the station’s robotic arm, he was maneuvered into place to install a new HD camera. Who was moving the arm? Astronauts inside the station were carefully moving it into place!
And, ta da! Below you can see one of the first views from the new enhanced HD camera…(sorry, not a GIF).
After Acaba installed the new HD camera, he repaired the camera system on the end of the robotic arm’s hand. This ensures that the hand can see the vehicles that it’s capturing.
Bresnik, completed all of his planned tasks and moved on to a few “get ahead” tasks. He first started removing extra thermal insulation straps around some spare pumps. This will allow easier access to these spare parts if and when they’re needed in the future.
He then worked to install a new handle on the outside of space station. That’s a space drill in the above GIF.
After Acaba finished working on the robotic arm’s camera, he began greasing bearings on the new latching end effector (the arm’s “hand”), which was just installed on Oct. 5.
The duo completed all planned spacewalk tasks, cleaned up their work stations and headed back to the station’s airlock.
Once safely inside the airlock and pressure was restored to the proper levels, the duo was greeted by the crew onboard.
They took images of their spacesuits to document any possible tears, rips or stains, and took them off.
Coverage ended at 2:36 p.m. EDT after 6 hours and 49 minutes. We hope the pair was able to grab some dinner and take a break!
You can watch the entire spacewalk HERE, or follow @Space_Station on Twitter and Instagram for regular updates on the orbiting laboratory.
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Scientists fine-tune organic thin films with an eye toward biomedical devices
Using DNA from salmon, researchers in South Korea hope to make better biomedical and other photonic devices based on organic thin films. Often used in cancer treatments and health monitoring, thin films have all the capabilities of silicon-based devices with the possible added advantage of being more compatible with living tissue.
A thin film is just what it sounds like, a layer of material only nanometers or micrometers thick that can be used to channel light. If the film is a dielectric – that is, an insulator such as glass – it can be used without worrying that it might conduct electricity.
“DNA is the most abundant organic material, and it is a transparent dielectric, comparable to silica,” said Kyunghwan “Ken” Oh, of the Photonic Device Physics Laboratory at Yonsei University, Seoul, South Korea. In the journal Optical Materials Express, from The Optical Society (OSA), Oh and his colleagues lay out their method for fabricating the thin films in a way that gives them fine control over the material’s optical and thermal properties.
As the basis for the silica glass that makes up optical fibers, silicon has long been a dominant material in inorganic photonic devices because it’s readily available and easy to work with from the materials perspective. Oh argues that DNA can play the same role in organic photonic devices because it can be found throughout the living world. It could, for instance, be used to make waveguides similar to silica fibers to carry light within the body. Organic devices should also be easy to manufacture, more flexible than silicon and environmentally friendly.
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We are most familiar with the four conventional phases of matter: solid, liquid, gas, and plasma. Changes between two phases, known as phase transitions, are marked by abrupt changes in material properties such as density. In recent decades a wide body of physics research has been devoted to discovering new unconventional phases of matter, which typically emerge at ultra-low temperatures or in specially-structured materials. Exotic “topological” phases exhibit properties that can only change in a quantized (stepwise) manner, making them intrinsically robust against impurities and defects.
In addition to topological states of matter, topological phases of light can emerge in certain optical systems such as photonic crystals and optical waveguide arrays. Topological states of light are of interest as they can form the basis for future energy-efficient light-based communication technologies such as lasers and integrated optical circuits.
However, at high intensities light can modify the properties of the underlying material. One example of such a phenomenon is the damage that the high-power lasers can inflict on the mirrors and lenses. This in turn affects the propagation of the light, forming a nonlinear feedback loop. Nonlinear optical effects are essential for the operation of certain devices such as lasers, but they can lead to the emergence of disorder from order in a process known as modulational instability, as is shown in Figure 1. Understanding the interplay between topology and nonlinearity is a fascinating subject of ongoing research.
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This week, a suite of 46 separate scientific papers describe different aspects of the giant planet Jupiter, from its massive polar cyclones, to its complex magnetic field, to its unique radiation environment. The papers mark the first full scientific results from NASA’s Juno mission, which arrived in orbit around Jupiter last summer. Later this July, the craft is slated to overfly the planet’s Great Red Spot, bringing back still more data. Juno program scientist Jared Espley and Juno radiation monitoring investigation lead Heidi Becker join Ira to sum up some of the Jovian surprises, as well as give a preview of what still lies ahead for the Juno mission. Listen here to learn more.
[Photos by NASA/JPL/MSSS/Gerald Eichstädt/Justin Cowart/Alexis Tranchandon/Solaris]
Materials research creates potential for improved computer chips and transistors
It’s a material world, and an extremely versatile one at that, considering its most basic building blocks – atoms – can be connected together to form different structures that retain the same composition.
Diamond and graphite, for example, are but two of the many polymorphs of carbon, meaning that both have the same chemical composition and differ only in the manner in which their atoms are connected. But what a world of difference that connectivity makes: The former goes into a ring and costs thousands of dollars, while the latter has to sit content within a humble pencil.
The inorganic compound hafnium dioxide commonly used in optical coatings likewise has several polymorphs, including a tetragonal form with highly attractive properties for computer chips and other optical elements. However, because this form is stable only at temperatures above 3100 degrees Fahrenheit – think blazing inferno – scientists have had to make do with its more limited monoclinic polymorph. Until now.
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Depositing books due at the library, the grad student takes a humiliating whirlwind tour of everything his past self had planned to read.
For her performance in Gone with the Wind (1939), Hattie McDaniel won a Best Supporting Actress Oscar on February 29, 1940. She was the first African American to win an Academy Award.
“I was on a leadership team in 5th grade. At the end of the year we were supposed to take a trip to Washington DC. We held fundraisers and everything. But when it was time to go, I didn’t have the identification papers to buy a plane ticket. So our teacher Ms. Rivera decided that we’d take a bus. Just so I could go too. That trip changed my life. It made me want to be a lawyer. And Ms. Rivera became one of the closest people in my life. She always kept in touch. She basically watched me grow up. One time in high school I got in a huge fight with my mom, and Ms. Rivera came and took me on a long car ride. I started to tell her everything. I told her about a recent break-up, and how I smoked weed, and ‘I did this,’ and ‘I did that.’ She just listened to everything. Then she started telling me about her life too. She told me that she’d been in an abusive relationship. I’d always thought her life was perfect because she was a guidance counselor. But she’d been through so much too. When it was came time to apply for college, Ms. Rivera was the one who helped me apply for DACA. She told me about the TheDream.us scholarship. I didn’t even want to apply. I was ready to give up. I’d just accepted that I’d always work in restaurants like my mom. But Ms. Rivera made me apply. She said: ‘What happened to that girl who wanted to be a lawyer?’ I learned that I got the scholarship in February. They’re paying for my entire college. Ms. Rivera was so proud of me. She kept saying: ‘I told you so.’”