However, they also found the process need more steps if the blended fabric was dyed or treated with chemicals that increase wrinkle resistance.

“We can separate all of the cotton out of a cotton-polyester blend, meaning now we have clean polyester that can be recycled,” said the study’s corresponding author Sonja Salmon, associate professor of textile engineering, chemistry and science at NC State. “In a landfill, the polyester is not going to degrade, and the cotton might take several months or more to break down. Using our method, we can separate the cotton from polyester in less than 48 hours.”

According to the U.S. Environmental Protection Agency, consumers throw approximately 11 million tons of textile waste into U.S. landfills each year. Researchers wanted to develop a method of separating the cotton from the polyester so each component material could be recycled.

In the study, researchers used a “cocktail” of enzymes in a mildly acidic solution to chop up cellulose in cotton. Cellulose is the material that gives structure to plants’ cell walls. The idea is to chop up the cellulose so it will “fall out” out of the blended woven structure, leaving some tiny cotton fiber fragments remaining, along with glucose. Glucose is the biodegradable byproduct of degraded cellulose. Then, their process involves washing away the glucose and filtering out the cotton fiber fragments, leaving clean polyester.

“This is a mild process — the treatment is slightly acidic, like using vinegar,” Salmon said. “We also ran it at 50 degrees Celsius, which is like the temperature of a hot washing machine.

“It’s quite promising that we can separate the polyester to a clean level,” Salmon added. “We still have some more work to do to characterize the polyester’s properties, but we think they will be very good because the conditions are so mild. We’re just adding enzymes that ignore the polyester.”

They compared degradation of 100% cotton fabric to degradation of cotton and polyester blends, and also tested fabric that was dyed with red and blue reactive dyes and treated with durable press chemicals. In order to break down the dyed materials, the researchers had to increase the amount of time and enzymes used. For fabrics treated with durable press chemicals, they had to use a chemical pre-treatment before adding the enzymes.

“The dye that you choose has a big impact on the potential degradation of the fabric,” said the study’s lead author Jeannie Egan, a graduate student at NC State. “Also, we found the biggest obstacle so far is the wrinkle-resistant finish. The chemistry behind that creates a significant block for the enzyme to access the cellulose. Without pre-treating it, we achieved less than 10% degradation, but after, with two enzyme doses, we were able to fully degrade it, which was a really exciting result.”

Researchers said the polyester could be recycled, while the slurry of cotton fragments could be valuable as an additive for paper or useful addition to composite materials. They’re also investigating whether the glucose could be used to make biofuels.

“The slurry is made of residual cotton fragments that resist a very powerful enzymatic degradation,” Salmon said. “It has potential value as a strengthening agent. For the glucose syrup, we’re collaborating on a project to see if we can feed it into an anaerobic digester to make biofuel. We’d be taking waste and turning it into bioenergy, which would be much better than throwing it into a landfill.”

The study, “Enzymatic textile fiber separation for sustainable waste processing,” was published in Resources, Environment and Sustainability. Co-authors included Siyan Wang, Jialong Shen, Oliver Baars and Geoffrey Moxley. Funding was provided by the Environmental Research and Education Foundation, Kaneka Corporation and the Department of Textile Engineering, Chemistry and Science at NC State.

Two of the studies, led by Pietro Lampertico, MD, PhD, Division of Gastroenterology and Hepatology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy, were designed to assess the effectiveness and safety of patients with advanced HDV-related compensated cirrhosis being treated with BLV 2mg monotherapy and the consequences of discontinuing this treatment.

“HDV is the most severe form of chronic viral hepatitis,” explained Dr. Lampertico. “For many years, the only therapeutic option was the off-label administration of pegylated-interferon-alpha (PegIFNa), an approach characterized by suboptimal efficacy, an unfavorable safety profile and several contraindications.”

In a study of 18 patients with HDV-related advanced cirrhosis treated with BLV 2 mg/day for 48 weeks, Dr. Lampertico and colleagues demonstrated significant virological, biochemical and combined response rates associated with improvement of liver function.

“The efficacy and safety of BLV monotherapy in patients with advanced compensated cirrhosis were unknown before this study. Virological and biochemical responses to BLV monotherapy that we observed in our difficult-to-treat patients with HDV-related compensated cirrhosis were similar to those shown in the phase III registration study,” Dr. Lampertico noted.

In a case report, Dr. Lampertico and co-investigators demonstrated that HDV could be successfully eradicated from both serum and liver following a three-year course of BLV monotherapy, despite the persistence of HBsAg, in a patient with HDV-related compensated cirrhosis and esophageal varices. During the 72-week off-BLV follow-up, liver biopsy, intrahepatic HDV RNA and hepatitis D antigen were undetectable, less than 1% of hepatocytes were HBsAg positive and all were negative for hepatitis B core antigen.

“We were surprised to demonstrate that HDV can be eradicated following a finite course of an entry inhibitor administered as monotherapy such as BLV 2mg/day, despite the persistence of HBsAg positivity,” commented Dr. Lampertico.

In a study in JHEP Reports led by PD Dr. med. Katja Deterding, MD, Department. of Gastroenterology, Hepatology and Endocrinology at Hannover Medical School, Hannover, Germany, investigators report the first data from the largest multicenter cohort of patients to date who were treated with BLV under real-world conditions, including 50 patients with signs of significant portal hypertension, elevated pressure in the major vein that leads to the liver.

The retrospective analysis of 114 cases covered 4,289 patient weeks of BLV treatment. Viral response was observed in 87 cases while hepatic inflammation improved, and treatment was well tolerated. More than 50% of patients showed a virologic response with less than 10% of patients not achieving an HDV RNA drop of at least 90% after 24 weeks. An improvement of biochemical hepatitis activity as measured by the liver enzyme alanine transaminase (ALT) values was observed regardless of virologic response. Investigators concluded that treatment was safe and well tolerated and associated with improvements in liver cirrhosis and portal hypertension with prolonged treatment.

“In line with other real-world cohorts and clinical trials our real-world study confirms the antiviral activity of BLV,” noted Dr. Deterding. “We were surprised to see an improvement in biochemical hepatitis activity even in cases without viral response. Potential explanations for this phenomenon include anti-inflammatory properties of BLV.”

“This is the first time that patients with HDV-related chronic advanced liver disease can be treated with an antiviral therapy since 1977 when HDV was discovered. Long-term suppressive therapy with BLV 2 mg/day has the potential to improve survival, of these difficult-to-treat patients for the first time in 45 years,” concluded Dr. Lampertico. “We also found that BLV treatment can be successfully discontinued in some HDV patients who achieved long-term viral suppression while on therapy.”

HDV infection occurs when people become infected with both hepatitis B and D virus either simultaneously (co-infection) or acquire the hepatitis D virus after first being infected with hepatitis B (super-infection). According to the World Health Organization, HDV affects nearly 5% of individuals with a chronic infection resulting from hepatitis B virus (HBV). Populations that are more likely to have HBV and HDV co-infection include indigenous populations, recipients of hemodialysis and individuals who inject drugs.

This ability to control light using a semiconductor device could allow low-power, relatively inexpensive sources like LEDs or flashlight bulbs to replace more powerful laser beams in new technologies such as holograms, remote sensing, self-driving cars and high-speed communication.

“What we’ve done is show that steering a beam of incoherent light can be done,” said Prasad Iyer, Sandia scientist and lead author of the research, which was reported in the current issue of the journal Nature Photonics. The work was funded by the Department of Energy’s Office of Science.

Incoherent light is emitted by many common sources, such as an old-fashioned incandescent light bulb or an LED bulb. This light is called incoherent since the photons are emitted with different wavelengths and in a random fashion. A beam of light from a laser, however, does not spread and diffuse because the photons have the same frequency and phase and is thus called coherent light.

In the team’s research, they manipulated incoherent light by using artificially structured materials called metasurfaces, made from tiny building blocks of semiconductors called meta-atoms that can be designed to reflect light very efficiently. Although metasurfaces had previously shown promise for creating devices that could steer light rays to arbitrary angles, they also presented a challenge because they had only been designed for coherent light sources. Ideally, one would want a semiconductor device that can emit light like an LED, steer the light emission to a set angle by applying a control voltage and shift the steering angle at the fastest speed possible.

The researchers started with a semiconductor metasurface that had embedded tiny light sources called quantum dots. By using a control optical pulse, they were able to change, or reconfigure, the way the surface reflected light and steer the light waves emitted from the quantum dots in different directions over a 70-degree range for less than a trillionth-of-a-second, marking a significant success. Similar to laser-based steering, the steered beam restrained the tendency of incoherent light to spread over a wider viewing angle and instead produced bright light at a distance.

Taming light

A feat previously considered impossible, the team’s proof-of-principle work paves the way for developments in the fields of nanophotonics and ultrafast optics. The ability to dynamically control incoherent light sources and manipulate their properties offers a wide range of applications.

One low-power use would be to brighten military helmet screens used to overlay maps or blueprints over ordinary vision. “In applications where space is valuable,” Iyer said, “steering light emission with low-size-and-weight metasurface-LED displays could be made possible in the future with this technology. We can use the light emitted in a better way rather than just turning them off and on.”

The technique could also provide a new kind of small display that can project holographic images onto eyeballs using low-power LEDs, a capability of particular interest for augmented and virtual reality devices. Other uses could be in self-driving cars where LIDAR is used to sense objects in the path of the car.

In terms of expressions of interest, the team has had several inquiries from commercial sources, said Sandia researcher Igal Brener, a paper author and lead scientist on the project. “A commercial product could be 5-10 years out, especially if we want to have all the functionality on-chip,” Brener said. “You wouldn’t use a control optical pulse to impart the changes in the metasurface needed to steer the light, but rather you would do this control electrically. We have ideas and plans, but it’s still early. Imagine an LED light bulb that can emit light to follow you. Then you wouldn’t waste all that illumination where there’s nobody. This is one of the many applications that we dreamed about with DOE years ago for energy efficiency for office lighting, for example.”

Similarly, tamed light may one day offer benefits in scenarios where focused illumination is only needed in a specific area of interest, such as surgery or in autonomous vehicles.

For incoherent light, the future is looking bright.

Sandia National Laboratories is a multimission laboratory operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration. Sandia Labs has major research and development responsibilities in nuclear deterrence, global security, defense, energy technologies and economic competitiveness, with main facilities in Albuquerque, New Mexico, and Livermore, California.

In the study, published March 16 in Nature Cell Biology, Dr. James Lo, associate professor of medicine at Weill Cornell Medicine, and colleagues measured gene expression in individual beta cells collected from mice to determine how many different types of beta cells exist in the pancreas. The team discovered four distinct beta cell types, including one that stood out. The cluster 1 group of beta cells produced more insulin than other beta cells and appeared better able to metabolize sugar. The study also showed that loss of this beta cell type might contribute to type 2 diabetes.

“Before this, people thought a beta cell was a beta cell, and they just counted total beta cells,” said Dr. Lo, who is also a member of the Weill Center for Metabolic Health and the Cardiovascular Research Institute at Weill Cornell Medicine and a cardiologist at NewYork-Presbyterian/Weill Cornell Medical Center. “But this study tells us it might be important to subtype the beta cells and that we need study the role of these special cluster 1 beta cells in diabetes.”

Drs. Doron Betel, Jingli Cao, Geoffrey Pitt and Shuibing Chen at Weill Cornell Medicine teamed up with Dr. Lo to carry out the study.

The investigators used a technique called single-cell transcriptomics to measure all the genes expressed in individual mouse beta cells and then used that information to group them into four types. The cluster 1 beta cells had a unique gene expression signature that included high expression of genes that help cellular powerhouses called mitochondria to break down sugar and power them to secrete more insulin. Additionally, they could distinguish the cluster 1 beta cells from the other beta cell types by its high expression of the CD63 gene, which enabled them to use the CD63 protein as a marker for this specific beta cell type.

“CD63 expression provided us a way to identify the cells without destroying them and allowed us to study the live cells,” he said.

When the team looked at both human and mouse beta cells, they found that cluster 1 beta cells with high CD63 gene expression produce more insulin in response to sugar than the three other types of beta cells with low CD63 expression.

“They are very high-functioning beta cells,” Dr. Lo said. “We think they may carry the bulk of the workload of producing insulin, so their loss might have profound impacts.”

In mice fed an obesity-inducing, high-fat diet and mice with type 2 diabetes, the numbers of these insulin-producing-powerhouse beta cells decreased.

“Because the numbers of cluster 1/high CD63 cells went down, you may have less insulin production, which may play a major role in diabetes development,” he said.

Transplanting beta cells with high CD63 production into mice with type 2 diabetes restored their blood sugar levels to normal. But removing the transplanted cells caused high blood sugar levels to return. Transplanting low CD63 production beta cells into the mice didn’t restore blood sugar to normal levels. The transplanted low CD63 beta cells instead appeared dysfunctional.

The discovery may have important implications for the use of beta cell transplants to treat diabetes, Dr. Lo said. For example, it may be better to transplant only high CD63- beta cells. He noted that it might also be possible to transplant fewer of these highly productive cells. Dr. Lo’s team also found that humans with type 2 diabetes had lower levels of high CD63 beta cells compared to those without diabetes.

Next, Dr. Lo and his colleagues would like to find out what happens to the high CD63-producing beta cells in mice with diabetes and how to keep them from disappearing.

“If we can figure out how to keep them around longer, surviving and functional, that could lead to better ways to treat or prevent type 2 diabetes,” he said.

They would also like to study how existing diabetes treatments affect all types of beta cells. GLP-1 agonists, which help increase the release of insulin in people with diabetes, interact with high and low CD63-producing beta cells.

“Our study also shows that GLP-1 agonists might also be a way to get the low CD63-producing beta cells to work better,” Dr. Lo said.

Even though advances in 3D printing enable rapid fabrication of rotational mechanisms, integrating sensors into the designs is still notoriously difficult. Due to the complexity of the rotating parts, sensors are typically embedded manually, after the device has already been produced.

However, manually integrating sensors is no easy task. Embed them inside a device and wires might get tangled in the rotating parts or obstruct their rotations, but mounting external sensors would increase the size of a mechanism and potentially limit its motion.

Instead, the new system the MIT researchers developed enables a maker to 3D print sensors directly into a mechanism’s moving parts using conductive 3D printing filament. This gives devices the ability to sense their angular position, rotation speed, and direction of rotation.

With their system, called MechSense, a maker can manufacture rotational mechanisms with integrated sensors in just one pass using a multi-material 3D printer. These types of printers utilize multiple materials at the same time to fabricate a device.

To streamline the fabrication process, the researchers built a plugin for the computer-aided design software SolidWorks that automatically integrates sensors into a model of the mechanism, which could then be sent directly to the 3D printer for fabrication.

MechSense could enable engineers to rapidly prototype devices with rotating parts, like turbines or motors, while incorporating sensing directly into the designs. It could be especially useful in creating tangible user interfaces for augmented reality environments, where sensing is critical for tracking a user’s movements and interaction with objects.

“A lot of the research that we do in our lab involves taking fabrication methods that factories or specialized institutions create and then making then accessible for people. 3D printing is a tool that a lot of people can afford to have in their homes. So how can we provide the average maker with the tools necessary to develop these types of interactive mechanisms? At the end of the day, this research all revolves around that goal,” says Marwa AlAlawi, a mechanical engineering graduate student and lead author of a paper on MechSense.

AlAlawi’s co-authors include Michael Wessely, a former postdoc in the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) who is now an assistant professor at Aarhus University; and senior author Stefanie Mueller, an associate professor in the MIT departments of Electrical Engineering and Computer Science and Mechanical Engineering, and a member CSAIL; as well as others at MIT and collaborators from Accenture Labs. The research will be presented at the ACM CHI Conference on Human Factors in Computing Systems.

Built-in sensing

To incorporate sensors into a rotational mechanism in a way that would not disrupt the device’s movement, the researchers leveraged capacitive sensing.

A capacitor consists of two plates of conductive material that have an insulating material sandwiched between them. If the overlapping area or distance between the conductive plates is changed, perhaps by rotating the mechanism, a capacitive sensor can detect resulting changes in the electric field between the plates. That information could then be used to calculate speed, for instance.

“In capacitive sensing, you don’t necessarily need to have contact between the two opposing conductive plates to monitor changes in that specific sensor. We took advantage of that for our sensor design,” AlAlawi says.

Rotational mechanisms typically consist of a rotational element located above, below, or next to a stationary element, like a gear spinning on a static shaft above a flat surface. The spinning gear is the rotational element and the flat surface beneath it is the stationary element.

The MechSense sensor includes three patches made from conductive material that are printed into the stationary plate, with each patch separated from its neighbors by nonconductive material. A fourth patch of conductive material, which has the same area as the other three patches, is printed into the rotating plate.

As the device spins, the patch on the rotating plate, called a floating capacitor, overlaps each of the patches on the stationary plate in turn. As the overlap between the rotating patch and each stationary patch changes (from completely covered, to half covered, to not covered at all), each patch individually detects the resulting change in capacitance.

The floating capacitor is not connected to any circuitry, so wires won’t get tangled with rotating components.

Rather, the stationary patches are wired to electronics that use software the researchers developed to convert raw sensor data into estimations of angular position, direction of rotation, and rotation speed.

Enabling rapid prototyping

To simplify the sensor integration process for a user, the researchers built a SolidWorks extension. A maker specifies the rotating and stationary parts of their mechanism, as well as the center of rotation, and then the system automatically adds sensor patches to the model.

“It doesn’t change the design at all. It just replaces part of the device with a different material, in this case conductive material,” AlAlawi says.

The researchers used their system to prototype several devices, including a smart desk lamp that changes the color and brightness of its light depending on how the user rotates the bottom or middle of the lamp. They also produced a planetary gearbox, like those that are used in robotic arms, and a wheel that measures distance as it rolls across a surface.

As they prototyped, the team also conducted technical experiments to fine-tune their sensor design. They found that, as they reduced the size of the patches, the amount of error in the sensor data increased.

“In an effort to generate electronic devices with very little e-waste, we want devices with smaller footprints that can still perform well. If we take our same approach and perhaps use a different material or manufacturing process, I think we can scale down while accumulating less error using the same geometry,” she says.

In addition to testing different materials, AlAlawi and her collaborators plan to explore how they could increase the robustness of their sensor design to external noise, and also develop printable sensors for other types of moving mechanisms.

This research was funded, in part, by Accenture Labs.