【推荐1】In the future, chances are we don’t need to depend on human donations for life-saving skin grafts (移植).

That’s the goal of Xeno Therapeutics, a biotech non-profit organization. The US Food and Drug Administration approved the group’s initial application for temporary skin grafts removed from genetically modified (基因改良) pigs. This means that they can start testing pig skin grafts on people who have experienced severe burns.

Skin, the body’s largest organ, plays an important role in blocking pathogens (病原体) from reaching our organs inside. It also helps the body keep a constant temperature. People with severe skin damage are at a high risk of developing deadly infections as a result of changes in temperature.

At the moment, the only skin grafts available in the US come from the dead people who have agreed to be organ donors, or patients who have gone through surgery to remove skin after large weight loss. These human skins used for grafts are not easy to find.

Xeno Therapeutics, which gets its name from animal-to-human transplants, has raised pigs that have skin remarkably similar to our own. Grafts from these pigs are therefore more likely to hide without being detected by the host's immune system — at least temporarily. The idea is that they could be used for immediate burn treatment, followed human skin graft treatment later.

“I’d say that just like comparing a Coke with Pepsi, it would be hard to tell which was the human skin and which was the pig graft,” said Xeno Therapeutics CEO Paul Holzer.

The non-profit organization has been working to conduct the clinical trials, which will only be testing the grafts’ safety and tolerability in six patients with severe burns. Assuming the results are positive after a month, the grafts will need to pass through two more stages of testing before they can be approved for widespread clinical use.

Several other groups around the world are working to make animal organs suitable for clinical medicine. In Brazil, researchers are exploring using tilapia skin as temporary bandages for burn victims whose skin is regrowing.

【推荐2】People who have lost the ability to understand or use words due to brain damage are called aphasics (失语症患者). Such patients can be extremely good at something else. From the changing expressions on speakers’ faces and the tones of their voices, they can tell lies from truths.

Doctors studying the human brain have given a number of examples of this amazing power of aphasics. Some have even compared this power to that of a dog with an ability to find out the drugs hidden in the baggage.

Recently, scientists carried out tests to see if all that was said about aphasics was true. THEY STUDIED A MIXED GROUP OF PEOPLE. Some were normal; others were aphasics. It was proved that the aphasics were far ahead of the normal people in recognizing false speeches—in most cases, the normal people were fooled by words, but the aphasics were not.

Some years ago, Dr. Oliver Sacks wrote in his book about his experiences with aphasics. He mentioned a particular case in a hospital. Some aphasics were watching the president giving a speech on TV. Since the president had been an actor earlier, making a good speech was no problem for him. He was trying to put his feelings into every word of his speech.

But his way of speaking had the opposite effect on the patients. They didn’t seem to believe him. Instead, they burst into laughter. The aphasics knew that the president did not mean a word of what he was saying. He was lying!

Many doctors see aphasics as people who are not completely normal because they lack the ability to understand words. However, according to Dr. Sacks, they are more gifted than normal people. Normal people may get carried away by words. Aphasics seem to understand human expressions better, though they cannot understand words.

【推荐2】We know that our pet dogs and cats can recognize our faces, but our pet fish? A team of scientists from the UK and Australia have discovered that archerfish (喷水鱼) can distinguish human faces!

This marks the first time that a species of fish has shown such an ability. Such abilities have been previously shown in birds, but unlike fish, they have been proven to possess structures similar to the neocortex (大脑新皮层), the researchers added.

“Being able to distinguish between a large number of human faces is a surprisingly difficult task,” Dr. Newport said, “mainly due to the fact that all human faces share the same basic features.”

During their experiments, Dr. Newport and her colleagues presented archerfish with two images of human faces, and trained them to choose one by spitting jets (喷射流) of water at that picture. Next, the fish were presented with the familiar face and several that were unfamiliar, and were able to correctly pick the one that they had been trained to recognize, even when features such as head shape and color were removed from the selected pictures.

In the first experiment, the archerfish were tasked with picking the previously learned face from a group of 44 new ones, which they did with 81 percent accuracy. In the second, the researchers decided to make things a little harder. They took the pictures and made them black and white and evened out (使平均) the head shapes. You would think that would throw the fish for a loop. But no, they were able to pick the familiar face even then-and with more accuracy: 86%!

“Fish have a simpler brain than humans and entirely lack the section of the brain that humans use for recognizing faces. Despite this, fish may still be capable of finding the face they are trained to recognize,” Dr. Newport said, “The fact that archerfish can learn this task suggests that complicated brains are not necessarily needed to recognize human faces.”