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Breaking bonds: Double-helix unzipping reveals DNA physics

Accurately reconstructing how the parts of a complex molecular are held together knowing only how the molecule distorts and breaks up—this was the challenge taken on by a research team led by SISSA’s Cristian Micheletti and recently published on Physical Review Letters. In particular, the scientists studied how a DNA double helix unzips when translocated at high velocity through a nanopore, reconstructing fundamental DNA thermodynamic properties from the sole speed of the process.

The translocation of polymers through nanopores has long studied as a fundamental theoretical problem as well as for its several practical ramifications, e.g. for genome sequencing. We recall that the latter involves driving a DNA filament through a pore so narrow that only one of the double-helical strands can pass, while the other strand is left behind. As a result, the translocated DNA will necessarily split and unwind, an effect known as unzipping.

The research team, which also includes Antonio Suma from the University of Bari, first author, and Vincenzo Carnevale from Temple University, used a cluster of computers to simulate the process with different driving forces keeping track of the DNA’s unzipping speed, a type of data that has rarely been studied despite being directly accessible in experiments.

Job listing platform Indeed lays off 2,200 employees

At a company that helps people find jobs, 2,200 employees will now have to embark on a job search of their own. Indeed laid off 15% of employees today, CEO Chris Hyams announced in an all-hands meeting.

In a blog post, Hyams elaborated on the decision by explaining that the job market is expected to continue to cool down. Indeed makes its money by allowing companies to sponsor job listings, which shows the listing to more job seekers. But Hyams said that as of last quarter, sponsored job volumes were down 33% year over year, and total job openings were down 3.5%.

“With future job openings at or below pre-pandemic levels, our organization is simply too big for what lies ahead,” Hyams wrote. “We have held out longer than many other companies, but the revenue trends are undeniable. So I have decided to act now.”

New DART VADAR system allows development of precision RNA-based therapies

DART VADAR can automatically sense and respond to molecular triggers in cells.

During the COVID-19 pandemic, the term mRNA was brought to the public’s attention. It is, however, not a new medical technology, having been identified in 1961.

These mRNA vaccines were developed to generate a full-body immune response in order to protect the human body from the deadly coronavirus and its variants.


Dr_Microbe / iStock.

The rapid development of mRNA-based vaccines saved millions of lives worldwide. Since the beginning of the pandemic, up to twelve billion doses of mRNA vaccines have been administered globally.

New ‘biohybrid’ implant will restore function in paralyzed limbs

“This interface could revolutionize the way we interact with technology.”

Researchers from the University of Cambridge have created a new type of neural implant that could restore limb function in paralyzed limbs.

There have been former attempts at using neural implants to restore limb function, but these mostly failed. This is because scar tissue can envelop the electrodes over time, disrupting the connection between the device and the nerve.


University of Cambridge.

The developed device works in sync between the brain and paralyzed limbs — it combines flexible electronics and human stem cells to “better integrate” with the nerve and drive limb function, according to a press release.

We’re one step closer to a meaty cyberpunk future as scientists create a ‘living computer’ using 80,000 mouse brain cells

Scientists in the US managed to put together a living computer by cultivating over 80,000 mouse stem cells (opens in new tab) (via IT Home) (opens in new tab). One day, the hope is to have a robot that uses living muscle tissue to sense and process information about its environment.

Researchers at the University of Illinois have used tens of thousands of living mouse brain cells to build a computer that can recognize patterns of light and electricity. The team presented their findings at the American Institute of Physics in the form of a computer about the size of your palm.

New microchip links two Nobel Prize-winning techniques

Physicists at Delft University of Technology have built a new technology on a microchip by combining two Nobel Prize-winning techniques for the first time. This microchip could measure distances in materials at high precision—for example, underwater or for medical imaging.

Because the technology uses sound vibrations instead of light, it is useful for high-precision position measurements in opaque materials. The instrument could lead to new techniques to monitor the Earth’s climate and human health. The work is now published in Nature Communications.

The microchip mainly consists of a thin ceramic sheet that is shaped like a trampoline. This trampoline is patterned with holes to enhance its interaction with lasers and has a thickness about 1,000 times smaller than the thickness of a hair. As a former Ph.D. candidate in Richard Norte’s lab, Matthijs de Jong studied the small trampolines to figure out what would happen if they pointed a simple at them.

Why are colon cancer rates in young people rising?

In a recent perspective article published in the journal Science, researchers at the Young-Onset Colorectal Cancer Center of Dana-Farber Cancer Institute emphasized that a better understanding of the etiology of early-onset colorectal cancer (EOCRC) is crucial to managing its increasing incidence worldwide. So, they identified five critical areas for investigating EOCRC biology.

Perspective: A common cancer at an uncommon age. Image Credit: Anatomy Image / Shutterstock.

Immune signals that contribute to addiction vulnerability identified in the brain

For individuals suffering from drug addiction, certain cues—whether it’s specific people, places or things—can trigger powerful cravings for repeated use.

A new University of Michigan study has identified signals, traditionally associated with inflammation, contributing to people’s vulnerability to . With repeated drug use with the same exposure to cues, some individuals develop an inability to control their drug use, even in the face of negative consequences.

The study is published in the journal eNeuro.

Lab experiments suggest oxygen in early Earth’s atmosphere may have come from rocks

A team of geochemists from the Chinese Academy of Sciences, working with colleagues from the University of Hong Kong, Tianjin University and the University of California, has found evidence that suggests much of the oxygen in early Earth’s early atmosphere may have come from rocks. In their study, reported in Proceedings of the National Academy of Sciences, the group conducted lab experiments involving crushing rocks, exposing the results to water and measuring reactive oxygen species that were emitted.

Prior research has shown that Earth experienced what has been called the Great Oxidation Event approximately 2.3 to 2.4 billion years ago. During this time, microbe numbers increased dramatically, as they released during photosynthesis. But prior research has also suggested that a common life ancestor existed before the Great Oxidation Event, which further suggests that there was some amount of oxygen exposure. In this new effort, the researchers suggest that such oxygen could have come from rocks interacting with water.

The work involved crushing samples of quartz and then exposing them to water, which replicates some of the conditions that existed on early Earth prior to the rise of high levels of oxygen in the atmosphere. Adding water to freshly crushed quartz, the researchers found, led to reactions between the water and newly broken crystals. This resulted it the formation of molecular oxygen along with other like hydrogen peroxide. Such species are also known as free radicals and they would have played an important role in the evolution of . This is because by damaging DNA and other cell components, the would have pressured early life to adapt.

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