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Comment by Dr. Krishna Kumari Challa on December 22, 2020 at 9:44am

Researchers to resuscitate eyes, speed up clinical research for vision impairment

Researchers to resuscitate eyes, speed up clinical research for vision impairment

Researchers are developing a new method to bring eyes back to life from deceased body donors for clinical research purposes.

They are creating a device that resuscitates eyes from the dead.Vision impairment affects over 250 million people worldwide, with thirty-six million people being blind. Retinal degeneration is often incurable, and ageing populations worldwide are major social and economic challenges.

The device, codenamed ECaBox, will be a transparent, cubic box that mimics conditions in the living human eye, maintaining the eye’s temperature and pH levels while avoiding blood clots and removing metabolic waste and toxins. Inside the ECaBox will be donor human eyeballs. The immediate goal is to test novel stem cell therapies without fear of risking patient harm on this platform.

Artificial blood will also be developed to provide cells with oxygen and nutrients, kick-starting the activity of nerve cells and restoring total eye function. Artificial vitreous humour will maintain the eye’s ocular pressure.

The health of the eyeball will be continuously monitored to confirm retinal function and regeneration. Beyond this scope, this technology can be extended to keep donor eyes intact for transplantation purposes, extending the current 48-hour window limit.

For many patients whose hope to restore their vision rests on emerging therapeutics, this research will mean a quicker and safer development cycle that will lead to the treatments becoming available sooner

Current technological limitations mean that eyes can only be kept at 4ºC for a period of 48 hours before irreversible degradation. This greatly limits their use for experiments, particularly to test the effectiveness of new drugs and treatments.

While advances in human organoids, growing tissues in a petri dish, are successfully mimicking the function of the eye, they fail to encapsulate the eye’s physiological complexity, such as its immune, vasculature, and metabolism systems.

There are a huge number of potential new treatments and therapies for eye damage and vision loss, but the eyewatering cost of running a clinical trial can mean they never reach the market.”

This new method can greatly improve the preclinical validation steps for these treatments, supporting the screening of a larger number of candidates and helping promising drugs escape the ‘valley of death’ imposed by cost-benefit analyses in the pharmaceutical industry.

https://www.kcl.ac.uk/news/researchers-to-resuscitate-eyes-speed-up...

https://researchnews.cc/news/4226/Researchers-to-resuscitate-eyes--...

Comment by Dr. Krishna Kumari Challa on December 22, 2020 at 8:56am

Gravity Assist: The Bright Spot of the Asteroid Belt

Comment by Dr. Krishna Kumari Challa on December 22, 2020 at 8:52am

Cancer risk from obesity differs for men and women

 large study, published in BMC Medicine, included over 100,000* people. They found that a higher BMI (body mass index; a measure of total fat) is more dangerous for men, whereas a higher waist-to-hip ratio (your waist circumference divided by your hip circumference; a measure of abdominal fat) is more dangerous for women. To discover this, they used an approach, called Mendelian randomisation, that uses genetic information as a proxy measure for weight to investigate the effect of different body fat measures on colorectal cancer risk in men and women. An increase in BMI of about five kg/m2 raised the risk of colorectal cancer by 23 per cent for men, but only nine per cent for women. Whereas an equivalent increase in waist-to-hip ratio raised the risk for women by 25 per cent, this was only five per cent for men. 

http://www.bristol.ac.uk/news/2020/december/obesity-cancer.html

https://researchnews.cc/news/4229/Cancer-risk-from-obesity-differs-...

Comment by Dr. Krishna Kumari Challa on December 22, 2020 at 8:37am

Current food production systems could mean far-reaching habitat loss

The global food system could drive rapid and widespread biodiversity loss if not changed, new research has found.

The findings show that the global food system will need to be transformed to prevent habitat loss across the world. It shows that what we eat and how it is produced will need to change rapidly and dramatically to prevent widespread and severe biodiversity losses.

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The study estimated how food systems would affect biodiversity at a finer spatial scale than previous research (2.25 km²), making the results more relevant to conservation action by highlighting exactly which species and landscapes are likely to be threatened.

It did so by linking projections of how much agricultural land each country will need with a new model that estimates where agricultural expansion and abandonment are most likely to occur.

Proactive conservation to prevent habitat losses to agricultural expansion, Nature Sustainability (2020). DOI: 10.1038/s41893-020-00656-5 , www.nature.com/articles/s41893-020-00656-5

https://phys.org/news/2020-12-current-food-production-far-reaching-...

Comment by Dr. Krishna Kumari Challa on December 22, 2020 at 8:05am

When T-cells of our immune system become active, tiny traction forc...

When T-cells of our immune system become active, tiny traction forces at the molecular level play an important role. They have now been studied at TU Wien.

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Brazilian forests found to be transitioning from carbon sinks to ca...

A team of researchers affiliated with several institutions in Brazil has found that some non-Amazonian forests in Brazil have already begun to transition from carbon sinks to carbon sources. In their paper published in the journal Science Advances, the group describes their 33-year study of deciduous, semi-deciduous and evergreen forests in Brazil's state of Minas Gerais.

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Comment by Dr. Krishna Kumari Challa on December 22, 2020 at 8:02am

Evolution of a killer: How African Salmonella made the leap from gut to bloodstream

Scientists have exploited the combined power of genomics and epidemiology to understand how a type of Salmonella bacteria evolved to kill hundreds of thousands of immunocompromised people.

Bloodstream infections caused by a drug-resistant type of Salmonella Typhimurium called ST313 are a major public health concern in Africa, where the disease is endemic and causes ~50,000 deaths each year. What was missing was an understanding of the timing of the major evolutionary events that equipped African Salmonella to cause bloodstream infections in humans.

A team of researchers  sampled two comprehensive collections of Salmonella isolates from African patients with bloodstream infections, spanning 1966 to 2018, to piece together the evolutionary journey of the Salmonella over 50 years of human infections in Africa, including the discovery of a new lineage of antibiotic-susceptible ST313.

In the study, scientists sequenced the genomes of 680 Salmonella isolates, from archives kept by the Malawi Liverpool Wellcome Trust (MLW) clinical research programme and the Institute Pasteur, and used them to uncover the timeline of crucial genetic events responsible for the infection of immunocompromised humans by S. Typhimurium ST313. Mutations that influenced gene function during the evolution of ST313 were identified for the first time.

The team also discovered a new antibiotic-susceptible lineage of ST313 that emerged in Malawi in 2016 and is closely related to Salmonella variants that cause stomach infections in the United Kingdom and Brazil. The researchers speculate that changes in antibiotic usage in Malawi between 2002 and 2015 could have created a window of opportunity for the emergence of this new antibiotic-susceptible ST313 lineage.

Stepwise evolution of Salmonella Typhimurium ST313 causing bloodstream infection in Africa, Nature Microbiology (2020). DOI: 10.1038/s41564-020-00836-1 , www.nature.com/articles/s41564-020-00836-1

https://phys.org/news/2020-12-evolution-killer-african-salmonella-g...

Comment by Dr. Krishna Kumari Challa on December 21, 2020 at 10:40am

AI-powered microscope could check cancer margins in minutes

When surgeons remove cancer, one of the first questions is, “Did they get it all?” Researchers from Rice University and the University of Texas MD Anderson Cancer Center have created a new microscope that can quickly and inexpensively image large tissue sections, potentially during surgery, to find the answer. The microscope can rapidly image relatively thick pieces of tissue with cellular resolution, and could allow surgeons to inspect the margins of tumors within minutes of their removal. It was created by engineers and applied physicists at Rice and is described in a study published this week in the Proceedings of the National Academy of Sciences.

http://news.rice.edu/2020/12/17/ai-po...

Comment by Dr. Krishna Kumari Challa on December 21, 2020 at 10:08am

Fast walking in narrow corridors can increase COVID-19 transmission risk

Computational simulations have been used to accurately predict airflow and droplet dispersal patterns in situations where COVID-19 might be spread. In the journal Physics of Fluids, results show the importance of the shape of the space in modeling how virus-laden droplets move through the air.

The simulations are used to determine flow patterns behind a walking individual in spaces of different shape. The results reveal a higher transmission risk for children in some instances, such as behind quickly moving people in a long narrow hallway.

Previous investigations using this simulation technique have helped scientists understand the influence of objects, like glass barriers, windows, air conditioners, and toilets, on airflow patterns and virus spread. The previous simulations have usually assumed a large, open indoor space but have not considered the effect of nearby walls, like those that might exist in a narrow corridor.

If a person walking in a corridor coughs, their breath expels droplets that travel around and behind their body, forming a wake in the way a boat forms a wake in water as it travels. The investigation revealed the existence of a "re-circulation bubble" directly behind the person's torso and a long wake streaming out behind them at approximately waist height.

The flow patterns found are strongly related to the shape of the human body. At 2 meters downstream, the wake is almost negligible at mouth height and leg height but is still visible at waist height. 

Once the airflow patterns were determined, the investigation modeled the dispersal of a cloud of droplets expelled from the simulated person's mouth. The shape of the space surrounding the moving person is particularly critical for this part of the calculation.

Two types of dispersal modes were found. In one mode, the cloud of droplets detaches from the moving person and floats far behind that individual, creating a floating bubble of virus-laden droplets. In the other mode, the cloud is attached to the person's back, trailing behind them like a tail as they move through the space.

For the detached mode, the droplet concentration is much higher than for the attached mode, five seconds after a cough. This poses a great challenge in determining a safe social distance in places like a very narrow corridor, where a person may inhale viral droplets even if the patient is far in front of him or her.

The danger is particularly great for children, since in both modes, the cloud of droplets hovers at a distance above the ground that is about half the height of the infected person—in other words, at mouth level for children.

"Effects of space sizes on the dispersion of cough-generated droplets from a walking person," Physics of Fluids (2020). aip.scitation.org/doi/10.1063/5.0034874

https://phys.org/news/2020-12-fast-narrow-corridors-covid-transmiss...

Comment by Dr. Krishna Kumari Challa on December 20, 2020 at 12:29pm

Quantum Experiment Reveals Particles Can Form Collectives Out of Almost Nothing

How many particles do you need before individual atoms start behaving collectively? According to new research, the number is incredibly low. As few as six atoms will start transitioning into a macroscopic system, under the right conditions.

Using a specially designed ultra-cold laser trap, physicists observed the quantum precursor of the transition from a normal to a superfluid phase – offering a way to study the emergence of collective atomic behaviour and the limits of macroscopic systems.

Many-body physics is the field that seeks to describe and understand the collective behaviour of large numbers of particles: a bucket of water, for example, or a canister of gas. We can describe these substances in terms of their density, or their temperature – the way the substance is acting as a whole.

These are called macroscopic or many-body systems, and we can't understand them by just studying the behaviour of individual atoms or molecules. Rather, their behaviour emerges from the interactions between particles that individually do not have the same properties of the system as a whole.

Some examples of macroscopic behaviours that can't be described microscopically include collective excitations, such as the phonons that oscillate atoms in a crystal lattice. Phase transitions are another example – when a substance transitions from one phase to another – such as when ice melts into liquid, for example, or when liquid evaporates into a gas.

https://www.nature.com/articles/s41586-020-2936-y

https://www.sciencealert.com/quantum-simulator-reveals-that-phase-t...

 Here we observe the few-body precursor of a quantum phase transition from a normal to a superfluid phase. The transition is signalled by the softening of the mode associated with amplitude vibrations of the order parameter, usually referred to as a Higgs mode⁷. We achieve fine control over ultracold fermions confined to two-dimensional harmonic potentials and prepare closed-shell configurations of 2, 6 and 12 fermionic atoms in the ground state with high fidelity. 

Comment by Dr. Krishna Kumari Challa on December 19, 2020 at 12:38pm

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