For people who are unable to speak, signals of what they’d like to say hide in their brains. No one has been able to understand those signals directly. But researchers recently made progress in turning data from electrodes (电极) surgically placed on the brain into computer-made speech. Using computer models known as neural (神经) networks (NN), they reconstructed words and sentences that were, in some cases, understandable to human listeners.

People who have lost the ability to speak after a disease can use their eyes or make other small movements to select on-screen letters just like what Stephen Hawking did, but that was extremely inconvenient. But if NN could re-create their speech directly, they might regain much more: for example, the ability to cut in a fast-moving conversation.

The hurdles are high. “We are trying to work out the pattern of neurons that turn on and off at different time points, and infer the speech sounds,” says Nima Mesgarani, a computer scientist at Columbia University. “The mapping from one to the other is not straightforward at all.” How these signals translate to speech sounds varies from person to person, so computer models must be “trained” on each single patient. So you can imagine the work!

The network of Mesgarani’s team analyzed data from five patients who heard recordings of stories and people naming numbers from zero to nine. The computer then reconstructed spoken numbers from neural data alone; when the computer “spoke” the numbers, a group of listeners named them with 75% accuracy. Neurosurgeon Edward Chang reconstructed entire sentences from brain activity caught from speech and motor areas while three patients raised their voice and read. In an online test, 166 people heard one of the sentences and had to select it from among 10 written choices. Some sentences were correctly identified more than 80% of the time. The researchers also pushed the model further: They used it to re-create sentences from data recorded while people silently mouthed words. “That’s an important result—one step closer to the speech prosthesis (假肢) that we all have in mind,” one of the researchers said.

It's natural to think about what goes into producing the food in your daily lunch bag. But have you ever stopped to consider the production techniques behind the bag itself? At the center of it is a woman named Margaret Knight.

From her earliest years, Knight was a restless creator. In the article titled " The Evolution of the Grocery Bag", its writer mentions a few of her childhood projects. She was “famous for her kites", and "her sleds were the envy of the town’s boys.”

To support her mother, she took a job at a cotton factory when she was 12. That same year she invented a shuttle system which helped to prevent injury. At the time, she had no concept of patenting(得到……的专利权) her idea. What strengthened her place in history was her working experience at the Columbia Paper Bag Company. Here, instead of folding every paper bag by hand, Knight wondered if she might be able to make them cleanly and rapidly via an automated machine. The result was a working model of her elegant paper-folding machine. But this time: she wanted to go to the extra step and secure a patent on her creation, a brave move for a woman in the 19th century, when an extremely small percentage of patents were held by women.

Not only did Knight file for a patent, she bravely defended her owner ship of the bag machine idea. A man named Charles Annan said the creation was his own, arguing no woman could be able to design such a machine. Knight fought a legal battle against him and handed Anna a courtroom(法庭)defeat by presenting her detailed hand-drawn blueprints. Finally，Knight received her rightful patent in 1871.

After making the machine, she continued to invent many other things like a paper feeding machine and a skirt protector. Knight, at the age of seventy, worked twenty hours a day on 89th invention.

A sheet of transparent new material at a University of Maryland lab looks like it might be plastic. But it’s actually wood—and it could eventually be used to make energy-efficient windows or even see-through buildings. “Compared to glass, wood has lower heat conductivity, and it’s lighter, stronger, and more environmentally friendly,” says Liangbing Hu, a materials science professor at the University of Maryland.

The idea is to employ the material in buildings. With a window made from transparent wood instead of glass, for example, a building would take less energy to heat and cool. Because of the structure of the wood, the windows could also reduce glare from the sun while allowing in natural light.

Researchers have experimented with transparent wood in the past, but the new method is more sustainable. Other methods usually put the wood in a chemical compound Nacl to remove lignin, part of the wood that gives it structure. But this can weaken the wood, and produces unrecyclable waste. Hu and his team made slight changes. They removed only the parts of the lignin that give it color by brushing hydrogen peroxide (过氧化物) over the wood and leaving it under a UV light.

It’s just one of the ways scientists and engineers are rethinking how we can use this renewable resource in construction. Skyscrapers made entirely out of wood are gaining popularity in cities around the world. And scientists recently discovered a technique to grow wood in a lab, opening up the possibility of using wood without cutting down a forest.

The transparent wood is 50% stronger than previous transparent wood and could even be used to build load-bearing walls in a building. It could also potentially be used in other ways, such as layers used in solar cells. A new company called InventWood is working to commercialize the technology.