Chair, Microbiology & Immunology;
Walter schroeder professor in microbiology and immunology;
Medical College of Wisconsin.
Get the latest international news and world events from around the world.
Transistor-like MXene membranes enhance ion separation
By applying voltage to electrically control a new “transistor” membrane, researchers at Lawrence Livermore National Laboratory (LLNL) achieved real-time tuning of ion separations—a capability previously thought impossible. The recent work, which could make precision separation processes like water treatment, drug delivery and rare earth element extraction more efficient, was published in Science Advances.
The membranes are made of stacks of MXenes —2D sheets that are only a few atoms thick. Ions squeeze through nanoscale channels formed in the gaps between the stacked MXene layers.
Until now, scientists thought MXene membrane properties were intrinsic and unchangeable once created. The rate of ion transport was thought to be baked in from the beginning.
Health impacts of micro- and nanoplastic ingestion
The carcinogenic consequences of the plastic pollution crisis.
This Viewpoint by Jason A. Somarelli, Jason W. Arnold & Andrew B. West discusses the health impacts of micro-and nanoplastic ingestion: microplastics.
Address correspondence to: Jason A. Somarelli, 3,044 Genome Sciences Research Building I, 905 S. Lasalle St., Duke University Medical School, Durham, North Carolina 27,710, USA. Email: [email protected].
Routine vs Selective Calcium Supplementation After Thyroidectomy
Among adults undergoing total thyroidectomy, selective calcium and calcitriol supplementation triggered by low postoperative PTH was not superior to routine supplementation for preventing symptomatic or biochemical hypocalcemia.
Question Is selective calcium and calcitriol (C+C) supplementation, guided by postoperative PTH levels, a better strategy than routine supplementation for preventing symptomatic hypocalcemia after total thyroidectomy?
Findings In this randomized clinical trial of 258 patients, the incidence of symptomatic hypocalcemia in the selective C+C supplementation group (7.8%) compared with the routine C+C supplementation group (11.1%) was not signicantly different.
Meaning Selective C+C supplementation based on postoperative PTH levels is not superior to routine supplementation; both are viable options that can be used according to available resources and clinical context.
ALMA and JWST Identification of Faint Dusty Star-forming Galaxies up to z ∼ 8 and Their Connection with Other Galaxy Populations
A recent discovery in astrophysics could overturn our current models of the Universe! A team of astronomers led by UMass Amherst “stacked” observations between the ALMA telescope and the JWST to confirm approximately 70 faint dusty galaxies at the edge of our universe, which were formed almost 13 billion years ago 🌠🔭. This shows that stars were being formed earlier than our current models predict — turning everything we thought we knew upside down. What does this mean for the future of astrophysics? Find out here: https://ow.ly/Nab150Yil7i astronomy.
Zavala, Jorge A., Faisst, Andreas L., Aravena, Manuel, Casey, Caitlin M., Kartaltepe, Jeyhan S., Martinez, Felix, Silverman, John D., Toft, Sune, Treister, Ezequiel, Akins, Hollis B., Algera, Hiddo, Barboza, Karina, Battisti, Andrew J., Brammer, Gabriel, Cai, Zheng, Champagne, Jaclyn, Drakos, Nicole E., Egami, Eiichi, Fan, Xiaohui, Franco, Maximilien, Fudamoto, Yoshinobu, Fujimoto, Seiji, Gillman, Steven, Gozaliasl, Ghassem, Harish, Santosh, Jin, Xiangyu, Kakiichi, Koki, Kakkad, Darshan, Koekemoer, Anton M., Lin, Ruqiu, Liu, Daizhong, Long, Arianna S., Magdis, Georgios E., Manning, Sinclaire, Martin, Crystal L., McKinney, Jed, Meyer, Romain, Rodighiero, Giulia, Salazar, Victoria, Sanders, David B., Shuntov, Marko, Talia, Margherita, Tanaka, Takumi S.
Our brains may learn more from rare events than from repetition
More than a century ago, Pavlov trained his dog to associate the sound of a bell with food. Ever since, scientists have assumed the dog learned this through repetition. The more times the dog heard the bell and then got fed, the better it learned that the sound meant food would soon follow.
Now, scientists at UC San Francisco are upending this 100-year-old assumption about associative learning. The new theory asserts that it depends less on how many times something happens and more on how much time passes between rewards.
“It turns out that the time between these cue-reward pairings helps the brain determine how much to learn from that experience,” said Vijay Mohan K. Namboobidiri, Ph.D., an associate professor of Neurology and senior author of the study, published in Nature Neuroscience.
How fast is the universe expanding? Supernova could provide the answer
That the universe is expanding has been known for almost a hundred years now, but how fast? The exact rate of that expansion remains hotly debated, even challenging the standard model of cosmology. A research team at the Technical University of Munich (TUM), the Ludwig Maximilians University (LMU) and the Max Planck Institutes, MPA and MPE, has now imaged and modeled an exceptionally rare supernova that could provide a new, independent way to measure how fast the universe is expanding. The studies are published on the arXiv preprint server.
The supernova is a rare superluminous stellar explosion, 10 billion light-years away, and far brighter than typical supernovae. It is also special in another way: the single supernova appears five times in the night sky, like cosmic fireworks, due to a phenomenon known as gravitational lensing.
Two foreground galaxies bend the supernova’s light as it travels toward Earth, forcing it to take different paths. Because these paths have slightly different lengths, the light arrives at different times. By measuring the time delays between the multiple copies of the supernova, researchers can determine the universe’s present-day expansion rate, known as the Hubble constant.
Entangled Ions Measure Time Faster
An optical clock based on a pair of calcium ions achieves a given precision more quickly when the ions are entangled.
What time is it? How precisely you can answer this question might depend on how long you are able to measure. Glance at a clock and you’ll first register the positions of the hour and minute hands. Look for longer and you’ll make out the movement of the second hand, improving your precision 60-fold. The most precise timepieces currently available are state-of-the-art optical clocks, and these also return a more precise result the longer that they are interrogated. But for many applications—in satellite navigation systems, for example, where the position of a fast-moving vehicle needs to be determined quickly—the answer must be prompt as well as precise. Now Kai Dietze at the German National Metrology Institute and colleagues have demonstrated a way to use quantum entanglement to halve the measurement time of an ion-based optical clock without compromising its precision [1].
Optical clocks are the technological successors to microwave atomic clocks, which, for nearly 60 years, have defined the International System of Units (SI) unit of time: the second. Microwave atomic clocks have been refined since they were first invented in the 1950s, but now optical clocks are reaching maturity in the sense that several systems reach or exceed the criteria required by the International Bureau of Weights and Measures for redefining the second. Optical clocks could potentially outperform microwave clocks by 4 orders of magnitude, with implications for fundamental physics and geodesy.
