When a hungry worm encounters a rich food source, it immediately slows down so it can devour the feast. Once the worm is full, or the food runs out, it will begin roaming again.

A new study from MIT now reveals more detail about how the worm’s digestive tract signals the brain when to linger in a plentiful spot. The researchers found that a type of nerve cell found in the gut of the worm Caenorhabditis elegans is specialized to detect when bacteria are ingested; once that occurs, the neurons release a neurotransmitter that signals the brain to halt locomotion. The researchers also identified new ion channels that operate in this specialized nerve cell to detect bacteria.

The gut microbiome — the world of microbes that inhabit the human intestinal tract — has captured the interest of scientists and clinicians for its critical role in health. However, parsing which of those microbes are responsible for effects on our wellbeing remains a mystery.

Taking us one step closer to solving this puzzle, UC Santa Barbara physicists Eric Jones and Jean Carlson have developed a mathematical approach to analyze and model interactions between gut bacteria in fruit flies. This method could lead to a more sophisticated understanding of the complex interactions between human gut microbes.

The human ear, like those of other mammals, is so extraordinarily sensitive that it can detect sound-wave-induced vibrations of the eardrum that move by less than the width of an atom. Now, researchers at MIT have discovered important new details of how the ear achieves this amazing ability to pick up faint sounds.

The new findings help explain how our ears can detect vibrations a million times less intense than those we can detect through the sense of touch, for example. The results appear in the journal Physical Review Letters, in a paper by visiting scientist and lead author Jonathan Sellon, professor of electrical engineering and senior author Dennis Freeman, visiting scientist Roozbeh Ghaffari, and members of the Grodzinsky group at MIT.

MIT engineers have designed an ingestible, Jell-O-like pill that, upon reaching the stomach, quickly swells to the size of a soft, squishy ping-pong ball big enough to stay in the stomach for an extended period of time.

The inflatable pill is embedded with a sensor that continuously tracks the stomach’s temperature for up to 30 days. If the pill needs to be removed from the stomach, a patient can drink a solution of calcium that triggers the pill to quickly shrink to its original size and pass safely out of the body.

The new pill is made from two types of hydrogels — mixtures of polymers and water that resemble the consistency of Jell-O. The combination enables the pill to quickly swell in the stomach while remaining impervious to the stomach’s churning acidic environment.

A new device developed by Stanford University researchers could make it easier for doctors to monitor the success of blood vessel surgery. The sensor, detailed in a paper published Jan. 8 in Nature Biomedical Engineering, monitors the flow of blood through an artery. It is biodegradable, battery-free and wireless, so it is compact and doesn’t need to be removed and it can warn a patient’s doctor if there is a blockage.

“Measurement of blood flow is critical in many medical specialties, so a wireless biodegradable sensor could impact multiple fields including vascular, transplant, reconstructive and cardiac surgery,” said Paige Fox, assistant professor of surgery and co-senior author of the paper. “As we attempt to care for patients throughout the Bay Area, Central Valley, California and beyond, this is a technology that will allow us to extend our care without requiring face-to-face visits or tests.”

Some of the largest of these so-called bacteriophages have now been found in the human gut, where they periodically devastate bacteria just as seasonal outbreaks of flu lay humans low, according to a new study led by UC Berkeley scientists.

These “megaphages” — which have genomes about 10 times larger than the average phage and twice as big as any phage previously found in humans — were found in the human intestinal tract, but only from humans who eat a non-Western, high-fiber, low-fat diet.

Tellingly, they were also found in the guts of baboons and a pig, demonstrating that phages — which can carry genes that affect human health — can move between humans and animals and perhaps carry disease.

A team led by researchers at The University of Texas at Austin and Baylor College of Medicine has applied an unconventional approach involving bacteria to discover human proteins that can lead to DNA damage and promote cancer. This could lead to new tests to identify people who are likely to develop cancer. Reported in the journal Cell, the study also proposes biological mechanisms by which these proteins can damage DNA, opening possibilities for future cancer treatments.

“This study is opening up new avenues for discoveries of novel mechanisms that protect our genomes and how their dysfunction can alter the integrity of our DNA and cause cancer,” said co-corresponding author Kyle Miller, associate professor of molecular biosciences at UT Austin, who is also a member of the LIVESTRONG Cancer Institutes at the Dell Medical School and Baylor’s Dan L Duncan Comprehensive Cancer Center.

In rat models, the novel scaffolding mimicked natural anatomy and boosted stem cell-based treatment; the approach is scalable to humans and advances effort toward clinical trials

For the first time, researchers at University of California San Diego School of Medicine and Institute of Engineering in Medicine have used rapid 3D printing technologies to create a spinal cord, then successfully implanted that scaffolding, loaded with neural stem cells, into sites of severe spinal cord injury in rats.

The implants, described in a study published in the January 14 issue of Nature Medicine, are intended to promote nerve growth across spinal cord injuries, restoring connections and lost function. In rat models, the scaffolds supported tissue regrowth, stem cell survival and expansion of neural stem cell axons out of the scaffolding and into the host spinal cord.

Imagine a world where smartphones, laptops, wearables, and other electronics are powered without batteries. Researchers from MIT and elsewhere have taken a step in that direction, with the first fully flexible device that can convert energy from Wi-Fi signals into electricity that could power electronics.

Devices that convert AC electromagnetic waves into DC electricity are known as “rectennas.” The researchers demonstrate a new kind of rectenna, described in a study published in Nature that uses a flexible radio-frequency (RF) antenna that captures electromagnetic waves — including those carrying Wi-Fi — as AC waveforms.

One of the most cataclysmic events to occur in the cosmos involves the collision of two black holes. Formed from the deathly collapse of massive stars, black holes are incredibly compact—a person standing near a stellar-mass black hole would feel gravity about a trillion times more strongly than they would on Earth. When two objects of this extreme density spiral together and merge, a fairly common occurrence in space, they radiate more power than all the stars in the universe.

"Imagine taking 30 suns and packing them into a region the size of Hawaii. Then take two such objects and accelerate them to half the speed of light and make them collide. This is one of the most violent events in nature," says Vijay Varma, a graduate student at Caltech.

A weird feature of certain exotic materials allows electrons to travel from one surface of the material to another as if there were nothing in between. Now, researchers have shown that they can switch this feature on and off by toggling a material in and out of a stable topological state with pulses of light. The method could provide a new way of manipulating materials that could be used in future quantum computers and devices that carry electric current with no loss.

Topological materials are particularly interesting for these applications because their electronic states are extraordinarily resistant to external perturbations, such as heating, mechanical pressure and material defects. But to make use of these materials, scientists also need ways to fine-tune their properties

A new 3D printer uses light to transform gooey liquids into complex solid objects in only a matter of minutes.

Nicknamed the “replicator” by the inventors — after the Star Trek device that can materialize any object on demand — the 3D printer can create objects that are smoother, more flexible and more complex than what is possible with traditional 3D printers. It can also encase an already existing object with new materials — for instance, adding a handle to a metal screwdriver shaft — which current printers struggle to do.

The technology has the potential to transform how products from prosthetics to eyeglass lenses are designed and manufactured, the researchers say.

How smart is the form of artificial intelligence known as deep learning computer networks, and how closely do these machines mimic the human brain? They have improved greatly in recent years, but still have a long way to go, a team of UCLA cognitive psychologists reports in the journal PLOS Computational Biology.

Supporters have expressed enthusiasm for the use of these networks to do many individual tasks, and even jobs, traditionally performed by people. However, results of the five experiments in this study showed that it’s easy to fool the networks, and the networks’ method of identifying objects using computer vision differs substantially from human vision.

“The machines have severe limitations that we need to understand,” said Philip Kellman, a UCLA distinguished professor of psychology and a senior author of the study. “We’re saying, ‘Wait, not so fast.’”

Two-dimensional (2D) transition metal dichalcogenides (TMDs) nanomaterials such as molybdenite (MoS₂), which possess a similar structure as graphene, have been donned the materials of the future for their wide range of potential applications in biomedicine, sensors, catalysts, photodetectors and energy storage devices. The smaller counterpart of 2D TMDs, also known as TMD quantum dots (QDs) further accentuate the optical and electronic properties of TMDs, and are highly exploitable for catalytic and biomedical applications. However, TMD QDs is hardly used in applications as the synthesis of TMD QDs remains challenging. 

Now, engineers from the National University of Singapore (NUS) have developed a cost-effective and scalable strategy to synthesise TMD QDs. The new strategy also allows the properties of TMD QDs to be engineered specifically for different applications, thereby making a leap forward in helping to realise the potential of TMD QDs.

A multidisciplinary team of researchers from Imperial College London led by Dr Firat Güder from the Department of Bioengineering have developed an innovative technique to print metals such as silver, gold and platinum onto natural fabrics.

They have also shown that the technique could be used to incorporate batteries, wireless technologies and sensors into fabrics like paper and cotton textiles.

Ultimately these technologies could be used for new classes of low-cost medical diagnostic tools, wirelessly powered sticker-sensors to measure air pollution or clothing with health monitoring capabilities.

A new, simple and inexpensive method that uses ultraviolet light to control particle motion and assembly within liquids could improve drug delivery, chemical sensors and fluid pumps. The method encourages particles — from plastic microbeads, to bacterial spores, to pollutants — to gather and organize at a specific location within a liquid and, if desired, to move to new locations. A paper describing the new method appears in the journal Angewandte Chemie.

“Many applications related to sensors, drug delivery, and nanotechnology require the precise control of the flow of fluids,” said Ayusman Sen, distinguished professor of chemistry at Penn State and senior author of the paper. “Researchers have developed a number of strategies to do so, including nanomotors and fluid pumps, but prior to this study we did not have an easy way to gather particles at a particular location so that they can perform a useful function and then move them to a new location so they can perform the function again.

You might say that Patrick McNamara is in a frightening line of work. As a sleep researcher, he’s hunting for new ways to treat people with nightmare disorder (also known as dream anxiety disorder). Being chased by a malevolent entity, McNamara says, is one of the most common recurring nightmares that patients report experiencing over and over again.

Antireflection (AR) coatings on plastics have a multitude of practical applications, including glare reduction on eyeglasses, computer monitors and the display on your smart-phone when outdoors. Now, researchers at Penn State have developed an AR coating that improves on existing coatings to the extent that it can make transparent plastics, such as Plexiglas, virtually invisible.

"This discovery came about as we were trying to make higher-efficiency solar panels," said Chris Giebink, associate professor of electrical engineering, Penn State. "Our approach involved concentrating light onto small, high-efficiency solar cells using plastic lenses, and we needed to minimize their reflection loss."