. Scientific Frontline

Thursday, December 15, 2022

Quenchbody Immunosensors Pave the Way to Quick and Sensitive COVID-19 Diagnostics

A new immunosensor based on Quenchbody technology shows great potential as a fast, inexpensive, and convenient tool to detect SARS-CoV-2. Developed by scientists at Tokyo Institute of Technology (Tokyo Tech) and Tokyo Medical and Dental University (TMDU), this highly efficient diagnostic approach will be useful not only for point-of-care testing, but also for high-throughput epidemiological studies of COVID-19 and other emerging infectious diseases.

The double-tagged Quenchbody immunosensor becomes fluorescent when its target antigen—the nucleocapsid protein from SARS-CoV-2—binds at the antigen-binding region of the antibody fragments. This approach is fast, cost-effective, and convenient to use in practice, making it ideal for point-of-care testing as well as batch processing of patient samples. 

The incredibly fast spread of COVID-19 throughout the world brought to light a very important fact: we need better methods to diagnose infectious diseases quickly and efficiently. During the early months of the pandemic, polymerase chain reaction (PCR) tests were one of the most widely used techniques to detect COVID-19. However, these viral RNA-based techniques require expensive equipment and reaction times longer than an hour, which renders them less than ideal for point-of-care testing.

Early green, early brown – climate change leads to earlier senescence in alpine plants

Alpine plants that start to grow earlier also start to age earlier. As is the case with the alpine vegetation in these containers, which were exposed to summer weather several months before the snow melted photograph taken in July
Photo Credit: P. Möhl

Global warming is leading to longer growing seasons worldwide, with many plants growing earlier in spring and continuing longer in autumn thanks to warmer temperatures—so is the general opinion. Now, however, plant ecologists at the University of Basel have been able to show that this is not the case for the most common type of alpine grassland in the European Alps, where an earlier start leads to earlier aging and leaves the grassland brown for months.

Spring 2022 was extremely warm, giving many plants an early start to the growing season. And the Swiss Alps were no exception, with the snow cover melting early and the underlying vegetation being quickly roused into growth. Researchers at the Department of Environmental Sciences at the University of Basel have investigated how such an early start affects the plants’ further development.

For their study, they removed intact blocks of alpine grassland and placed them in walk-in climate chambers at Basel’s Botanical Institute. Here, they left the vegetation to overwinter artificially in cold darkness, and then switched some of the blocks to summer conditions in February. A second group was left in the cold dark until April, before summer was introduced here as well. The researchers compared the growth and aging of these plants with their neighbors growing naturally at an elevation of 2,500 meters, which did not emerge from the snow until late June.

Wednesday, December 14, 2022

With Discovery, Oxygen's Role in Growth of Tumors Reconsidered

Structure of the HIF1A protein. Based on PyMOL rendering of PDB 1h2k Illustration
Credit: Emw
CC BY-SA 3.0

Yale researchers have made a discovery that changes conventional thinking about the role that oxygen plays in the growth of tumors—an area of cancer research that has been intensely studied in recent years.

The results, from the lab of Andre Levchenko, the John C. Malone Professor of Biomedical Engineering, are published in Cell Systems. Other groups collaborating on this study were directed by Chi V. Dang (Johns Hopkins University) and Kshitiz (University of Connecticut).

When tumors start running out of oxygen, they can switch on hypoxia-inducible factor (HIF-1alpha)—a transcription factor, which is a protein that controls the activity of genes. As a result of HIF-1alpha activation, the expression of hundreds of genes can change and dramatically alter the behavior of cancer cells. Although the increase in HIF-1alpha is thought to be steady, the new study led by Levchenko discovered that the levels of this molecule can also repeatedly rise and fall in small groups of cells, particularly in areas of high cell density. The effects of this oscillation are profound, as it allows cancer cells starving for oxygen to resume division and growth. It can also promote pro-cancer genes and inhibit anti-cancer genes.

Paris Agreement temperature targets may worsen climate injustice for many island states

A comparison of global greenhouse gas emissions from 1990 – 2018 shows the low emissions contribution of AOSIS nations (blue) and increasing levels of total global emissions (red).
Illustration Credit: Sadai et al., 10.1029/2022EF002940

While the world focuses on limiting the rise in global temperature to 1.5 or 2 degrees Celsius over the preindustrial average, increasing meltwater from ice sheets presents an existential threat to the viability of island and coastal nations throughout the world. Now, research from the University of Massachusetts Amherst, recently published in the journal Earth’s Future, shows that even the most optimistic temperature targets can lead to catastrophic sea-level rise, which has already begun and will affect low-lying nations for generations to come.

While rising temperatures are having many deleterious effects on global ecosystems, economies and human wellbeing, an interdisciplinary team of researchers at the University of Massachusetts emphasize that temperature alone is not a sufficient basis for climate policy. 

Laser controls ultra-fast water switches

The water is fanned out by a specially developed nozzle. Then the laser is passed through.
Photo Credit: Adrian Buchmann

Researchers are introducing a completely new concept for switches with unprecedented speed.

Researchers at the Ruhr University Bochum have developed an ultra-fast circuit based on water. Thanks to a short but strong laser pulse, the water can be reached within less than a billionth of a second (10th-12 Seconds) in a conductive state and behaves almost like a metal during this time. This makes the circuit faster than the fastest known switching speed of a semiconductor to date. Adrian Buchmann, Dr. Claudius Hoberg and Dr. Fabio Novelli from the Ruhr Explores Solvation Cluster of Excellence, in short RESOLV, report in the journal APL Photonics December 2022.

Laser lets the water behave like a fast switch

All computer arithmetic operations are based on circuits. The speed at which a component can switch between states zero and one ultimately determines the speed of the computer. Semiconductors that enable electrical circuits are installed in current computers. "They are naturally limited in speed," explains Claudius Hoberg.

New Study Sheds Light on Boric Acid Transport and Excretion in Marine Fish

Seawater is known to contain a significant concentration of boric acid, which can be toxic and deadly to living systems. As such, fish living in marine habitats need to be able to excrete boric acid in order to maintain a healthy boron balance. Tokyo Tech researchers have now identified the gene and mechanism of boric acid transport in seawater fish and contrasted it to freshwater species.

Marine fishes live in highly saline environments with ionic concentrations that are vastly different from their blood plasma. Seawater contains a variety of toxic ion species that can build up in the body if the fish does not excrete them. One example of this is boric acid, which—in small amounts—is a vital micronutrient for animals but can prove toxic in excess. Hence, marine fish must develop physiologic means to excrete boric acid. However, how they do this is, as yet, unknown. Now, an international team led by researchers from Tokyo Institute of Technology (Tokyo Tech) has unveiled and demonstrated the molecular mechanisms underlying boric acid secretion in marine pufferfish.

Associate Professor Akira Kato of Tokyo Tech is the principal author of the study, which was published in the Journal of Biological Chemistry. He tells us more about it. "We compared euryhaline pufferfish (which are pufferfish that can survive in varying levels of salinity) accustomed to saltwater, brackish water, and freshwater. On comparing fish from these three habitats, we found that the urine of a seawater pufferfish (Takifugu pufferfish) contained 300 times more boric acid than pufferfish blood, and 60 times more boric acid than seawater." The urine of freshwater fish contained almost 1000 times less boric acid than that of seawater pufferfish. These findings established that Takifugu pufferfish living in seawater excrete boric acid in their urine. Just like in humans, the process of excretion via urine in pufferfish is mediated by the kidneys.

Researchers find the snake clitoris

A death adder snake, also known as acanthophis antarcticus.
Photo Credit: Luke Allen.

An international team of researchers, led by the University of Adelaide has provided the first anatomical description of the female snake clitoris, in a first-of-its-kind study.

PhD Candidate Megan Folwell from the School of Biological Sciences, University of Adelaide, led the research.

“Across the animal kingdom female genitalia are overlooked in comparison to their male counterparts,” said Ms Folwell.

“Our study counters the long-standing assumption that the clitoris (hemiclitores) is either absent or non-functional in snakes.”

The research involved examination of female genitalia in adult snake specimens across nine species, compared to adult and juvenile male snake genitalia.

Associate Professor Kate Sanders, School of Biological Sciences, University of Adelaide, said: “We found the heart-shaped snake hemiclitores is composed of nerves and red blood cells consistent with erectile tissue - which suggests it may swell and become stimulated during mating. This is important because snake mating is often thought to involve coercion of the female – not seduction.”

Tuesday, December 13, 2022

Particles of Light May Create Fluid Flow, Data-Theory Comparison Suggests

Brookhaven Lab theorist Bjoern Schenke's hydrodynamic calculations match up with data from collisions of photons with atomic nuclei at the Large Hadron Collider's ATLAS detector, suggesting those collisions create a fluid of "strongly interacting" particles.
Photo Credit: Brookhaven National Laboratory

A new computational analysis by theorists at the U.S. Department of Energy’s Brookhaven National Laboratory and Wayne State University supports the idea that photons (a.k.a. particles of light) colliding with heavy ions can create a fluid of “strongly interacting” particles. In a paper just published in Physical Review Letters, they show that calculations describing such a system match up with data collected by the ATLAS detector at Europe’s Large Hadron Collider (LHC).

As the paper explains, the calculations are based on the hydrodynamic particle flow seen in head-on collisions of various types of ions at both the LHC and the Relativistic Heavy Ion Collider (RHIC), a DOE Office of Science user facility for nuclear physics research at Brookhaven Lab. With only modest changes, these calculations also describe flow patterns seen in near-miss collisions, where photons that form a cloud around the speeding ions collide with the ions in the opposite beam.

“The upshot is that, using the same framework we use to describe lead-lead and proton-lead collisions, we can describe the data of these ultra-peripheral collisions where we have a photon colliding with a lead nucleus,” said Brookhaven Lab theorist Bjoern Schenke, a coauthor of the paper. “That tells you there’s a possibility that, in these photon-ion collisions, we create a small dense strongly interacting medium that is well described by hydrodynamics—just like in the larger systems.”

Not everyone aware sustainable diets are about helping the planet

Sustainable diets
Photo Credit: yilmazfatih

A new study has found that young Brits would be willing to change to a more sustainable diet, but a lack of understanding about what that actually means is preventing many from doing so.

Many people are also uncertain about what changes they should make.

Sustainable diets are defined by the UN as “diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations.”

Previous research has suggested that 20-30% of environmental impacts in Europe and the UK originate from our diets, including impacts from food production, processing and retail. It is also now widely accepted that the consumption of meat and animal products typically has a higher environmental impact than plant-based foods.

“When thinking about how to live more sustainably, people seem to understand that this can mean taking fewer flights, using the car less, recycling more, but it seems that not everyone is aware of the difference that changing their diet can make as well,” explained Katherine Appleton, Professor of Psychology at Bournemouth University, who led the study.

Fossil site reveals giant arthropods dominated the seas 470 million years ago

Fossils from the Fezouata Shale. From left to right, a non-mineralized arthropod (Marrellomorpha), a palaeoscolecid worm and a trilobites.
Image Credit Emmanuel Martin.

Discoveries at a major new fossil site in Morocco suggest giant arthropods – relatives of modern creatures including shrimps, insects and spiders – dominated the seas 470 million years ago.

Early evidence from the site at Taichoute, once undersea but now a desert, records numerous large “free-swimming” arthropods.

More research is needed to analyze these fragments, but based on previously described specimens, the giant arthropods could be up to 2m long.

An international research team says the site and its fossil record are very different from other previously described and studied Fezouata Shale sites from 80km away.

They say Taichoute (considered part of the wider “Fezouata Biota”) opens new avenues for paleontological and ecological research.

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