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Comment by Dr. Krishna Kumari Challa on July 19, 2022 at 6:30am

A tear-soluble contact lens with silicon nanoneedles to treat eye diseases

a team of researchers  has developed a type of contact lens with embedded nanoneedles for treating eye diseases. In their paper published in the journal Science Advances, the group describes how they made their contact lens and how well it worked when tested on rabbits.

Current methods of delivering medications to the eye involve therapies that are applied directly to the outer eye or are injected into it. Neither method is optimal—applied medicines do not penetrate deep enough into the eye and injected medicines are painful and often lead to inflammation. In this new effort, the researchers have come up with a new approach—application of a nanoneedle infused contact lens.

The researchers began with the notion of imbedding nanoneedles into the eye that degrade over time, releasing medication—and the nanoneedles would be so small that they would not cause pain or discomfort. To get the nanoneedles into the eye, they would attach them to a contact lens that would dissolve soon after application to the eye.

The researchers began with the nanoneedles—they grew them using a silicon base, which ensured they would take a long time to dissolve in the eye. They also made them very small—10 times smaller than any that had been tried before. They also developed a unique way to make them, it involved growing the nanoneedles from a silicon and medication mix, then applying a polymer layer to crack them where they joined the silicon base. This involved coating the tiny needles with polymethyl methacrylate. Then the polymer was peeled off the wafer base. The researchers next coated the base of the nanoneedles with another polymer and then removed the first layer. That left the needles embedded in the second polymer material. Once the design was confirmed, the researchers repeated the process in a way that resulted in the base being formed into a contact-lens shape. The final step involved adding a second medication to the lens—one that would be applied to the eye all-at-once as the base dissolved.

The researchers tested their product on rabbit-models and found an almost complete reduction in corneal neovascularization after just 28 days. The group notes that much more work will need to be done before their nanoneedle-based therapy could be used to treat human patients. It will first have to be tested both for efficacy and safety, and also a means for storing the lens once created will need to be developed.

Woohyun Park et al, Biodegradable silicon nanoneedles for ocular drug delivery, Science Advances (2022). DOI: 10.1126/sciadv.abn1772

Comment by Dr. Krishna Kumari Challa on July 18, 2022 at 11:38am

Study: Sentences have their own connection in the brain

A new study finds that incoming speech sounds are connected by our brain to our knowledge of grammar, which is quite abstract in nature. But the big question is how does the brain process complex grammatical structures?

A group of researchers from the Max Planck Institute of Psycholinguistics and Radboud University in Nijmegen discovered that the brain encodes the structure of sentences (‘the vase is red’) and phrases (‘the red vase’) into various neural firing patterns.

The findings of the neuroimaging study were published in the PLOS Biology.

How does the brain represent sentences? This is one of the fundamental questions in neuroscience, because sentences are an example of abstract structural knowledge that is not directly observable from speech. While all sentences are made up of smaller building blocks, such as words and phrases, not all combinations of words or phrases lead to sentences.

In fact, listeners need more than just knowledge of which words occur together: they need abstract knowledge of language structure to understand a sentence. So how does the brain encode the structural relationships that make up a sentence?

The researchers created sets of spoken Dutch phrases (such as de rode vaas ‘the red vase’) and sentences (such as de vaas is rood ‘the vase is red’), which were identical in duration and number of syllables, and highly similar in meaning. They also created pictures with objects (such as a vase) in five different colours. Fifteen adult native speakers of Dutch participated in the experiment.

For each spoken stimulus, they were asked to perform one of three tasks in random order. The first task was structure-related, as participants had to decide whether they had heard a phrase or a sentence by pushing a button. The second and third task were meaning-related, as participants had to decide whether the colour or object of the spoken stimulus matched the picture that followed.

As expected from computational simulations, the activation patterns of neurons in the brain were different for phrases and sentences, in terms of both timing and strength of neural connections. These findings show how the brain separates speech into linguistic structure by using the timing and connectivity of neural firing patterns. These signals from the brain provide a novel basis for future research on how our brains create language.

https://theprint.in/science/study-sentences-have-their-own-connecti...

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Comment by Dr. Krishna Kumari Challa on July 18, 2022 at 9:56am

What is the difference between reproducibility and replicability?

 “Reproducibility” refers to instances in which the original researcher's data and computer codes are used to regenerate the results, while “replicability” refers to instances in which a researcher collects new data to arrive at the same scientific findings as a previous study.

Comment by Dr. Krishna Kumari Challa on July 17, 2022 at 12:48pm

Woodpeckers don’t have shock absorbers

Woodpeckers regularly smack their heads into trees at a rate of 20 times per second, seemingly without doing damage to their brains. Researchers have long thought the birds were somehow cushioning these blows to their brains with a spongy skull bone or elongated tongue. But researchers analysed high-speed footage of six woodpeckers and found that their heads moved just as fast as their beaks, and simulations found that they probably didn’t use shock absorption because it would require them to bang their heads harder. The study suggests that woodpeckers instead avoid concussions because of their brain’s small size and positioning.

Reference: Current Biology paper

Comment by Dr. Krishna Kumari Challa on July 17, 2022 at 12:47pm

One coronavirus infection wards off another

Data from Qatar suggest that natural immunity induced by infection with SARS-CoV-2 provides a strong shield against reinfection by a pre-Omicron variant for 16 months or longer. This protection against catching the virus dwindles over time, but immunity triggered by previous infection also thwarts the developme... — and this safeguard shows no signs of waning. Scientists also warn that the study’s results do not mean that infected people can skip vaccination. A separate study by many of the same authors found that people who had both natural immunity and vaccine immunity were substantially more protected against the virus than people who had only one of the two.

Reference: medRxiv preprint (not peer reviewed) & The New England Journal of Medicine paper

Comment by Dr. Krishna Kumari Challa on July 17, 2022 at 12:22pm

Two different white blood cell types play opposing roles in affecting heartbeat irregularities after heart attack

Patients with heart disease are at risk of experiencing a potentially lethal "electrical storm" involving recurrent episodes of a type of irregular heartbeat called ventricular tachycardia (VT).

Electric shock therapy is used to treat VT following a heart attack, but unfortunately, options to prevent VT recurrence are limited.

New research led by investigators at Massachusetts General Hospital reveals that two different white blood cell types influence VT in the heart, suggesting that treatments that influence these cells may help reduce patients' risk of sudden cardiac death.

The work, which is published in Nature Cardiovascular Research, is based on the knowledge that cardiac conditions (such as heart attacks) that increase the risk of VT and other heartbeat irregularities lead to massive changes in the white blood cell populations surrounding the heart.

To study the mechanisms involved, MGH scientists developed a new research model. "It was believed that mice don't get VT after a heart attack, but we discovered a surprisingly simple trick to induce it—feeding mice food with low potassium levels," says senior author Matthias Nahrendorf, MD, Ph.D., an investigator in MGH's Center for Systems Biology, Professor of Radiology at Harvard Medical School, and the Richard Moerschner Endowed MGH Research Institute Chair in Men's Health

"This is a major step forward because now we can study how different white blood cell subclasses influence heart rhythms. It is also clinically relevant because every fifth patient who experiences a heart attack has low blood potassium levels, and these patients are known to be particularly likely to develop heartbeat irregularities, or arrhythmia."

The team's experiments demonstrated that among the different white blood cell types, neutrophils promote VT while macrophages protect against it. "Inflammatory neutrophils give rise to arrhythmia by compromising the electrical function of heart muscle cells called cardiomyocytes," explains Nahrendorf.

"Macrophages, which take up debris, are protective, and deleting them gave rise to electrical storm in mice with low potassium levels who experienced a heart attack. Indeed, these mice were more likely to die from arrhythmia."

The findings indicate that additional research into the roles of white blood cells in arrhythmia could lead to new targeted therapies for irregular heart rhythms.

https://researchnews.cc/news/14300/Two-different-white-blood-cell-t...

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Comment by Dr. Krishna Kumari Challa on July 17, 2022 at 11:38am

Smart thermostats inadvertently strain electric power grids

Smart thermostats – those inconspicuous wall devices that help homeowners govern electricity usage and save energy – may be falling into a dumb trap.

Set by default to turn on before dawn, the smart thermostats unintentionally work in concert with other thermostats throughout neighborhoods and regions to prompting inadvertent, widespread energy-demand spikes on the grid.

The smart thermostats are saving homeowners money, but they are also initiating peak demand throughout the network at a bad time of day, according to  engineers in a forthcoming paper in Applied Energy (September 2022.)

https://news.cornell.edu/stories/2022/07/smart-thermostats-inadvert...

https://www.sciencedirect.com/science/article/abs/pii/S030626192200...

Comment by Dr. Krishna Kumari Challa on July 16, 2022 at 11:47am

Whole blood exchange could offer disease-modifying therapy for Alzheimer's disease, study finds

A novel, disease-modifying therapy for Alzheimer's disease may involve the whole exchange of blood, which effectively decreased the formation of amyloid plaque in the brains of mice, according to a new study.

A research team performed a series of whole blood exchange treatments to partially replace blood from mice exhibiting Alzheimer's disease-causing amyloid precursor proteins with complete blood from healthy mice of the same genetic background. The results of the study were published today in Molecular Psychiatry.

This article provides a proof-of-concept for the utilization of technologies commonly used in medical practice, such as plasmapheresis or blood dialysis, to 'clean' blood from Alzheimer's patients, reducing the buildup of toxic substances in the brain. This approach has the advantage that the disease can be treated in the circulation instead of in the brain.

Previous studies  have shown that the misfolding, aggregation, and buildup of amyloid beta proteins in the brain plays a central role in Alzheimer's disease. Therefore, preventing and removing misfolded protein aggregates is considered a promising treatment for the disease.

However, the treatment of Alzheimer's disease has long been complicated, due to the difficulty in delivering therapeutic agents across the blood-brain barrier. In this latest research, scientists have  discovered that manipulating circulating components in Alzheimer's disease could be the key to solving this issue.

After multiple blood transfusions, the researchers found that the development of cerebral amyloid plaques in a transgenic mice model of Alzheimer's disease was reduced by 40% to 80%. This reduction also resulted in improved spatial memory performance in aged mice with the amyloid pathology, and lowered the rates of plaque growth over time.

While the exact mechanism by which this blood exchange reduces amyloid pathology and improves memory is currently unknown, there are multiple possibilities. One possible explanation is that lowering amyloid beta proteins in the bloodstream may help facilitate the redistribution of the peptide from the brain to the periphery. Another theory is that blood exchange somehow prevents amyloid beta influx, or inhibits the re-uptake of cleared amyloid beta, among other potential explanations.

However, regardless of the mechanisms of action associated with the blood exchange treatment, the study shows that a target for Alzheimer's disease therapy may lie in the periphery.

 Preventive and therapeutic reduction of amyloid deposition and behavioral impairments in a mice model of Alzheimer's disease by whole blood exchange, Molecular Psychiatry (2022). DOI: 10.1038/s41380-022-01679-4

Comment by Dr. Krishna Kumari Challa on July 16, 2022 at 11:25am

Bacteria-based biohybrid microrobots on a mission to one day battle cancer

A team of scientists in the Physical Intelligence Department at the Max Planck Institute for Intelligent Systems have combined robotics with biology by equipping E. coli bacteria with artificial components to construct biohybrid microrobots. First, as can be seen in Figure 1, the team attached several nanoliposomes to each bacterium. On their outer circle, these spherical-shaped carriers enclose a material (ICG, green particles) that melts when illuminated by near infrared light. Further towards the middle, inside the aqueous core, the liposomes encapsulate water soluble chemotherapeutic drug molecules (DOX).

The second component the researchers attached to the bacterium is magnetic nano particles. When exposed to a magnetic field, the iron oxide particles serve as an on-top booster to this already highly motile microorganism. In this way, it is easier to control the swimming of bacteria—an improved design toward an in vivo application. Meanwhile, the rope binding the liposomes and magnetic particles to the bacterium is a very stable and hard to break streptavidin and biotin complex, which was developed a few years prior and reported in a Nature article, and comes in useful when constructing biohybrid microrobots.

E. coli bacteria are fast and versatile swimmers that can navigate through material ranging from liquids to highly viscous tissues. But that is not all, they also have highly advanced sensing capabilities. Bacteria are drawn to chemical gradients such as low oxygen levels or high acidity—both prevalent near tumor tissue. Treating cancer by injecting bacteria in proximity is known as bacteria mediated tumor therapy. The microorganisms flow to where the tumor is located, grow there and in this way activate the immune system of patients. Bacteria mediated tumor therapy has been a therapeutic approach for more than a century.

For the past few decades, scientists have looked for ways to increase the superpowers of this microorganism even further. They equipped bacteria with extra components to help fight the battle. However, adding artificial components is no easy task. Complex chemical reactions are at play, and the density rate of particles loaded onto the bacteria matters to avoid dilution. The team in Stuttgart has now raised the bar quite high. They managed to equip 86 out of 100 bacteria with both liposomes and magnetic particles.

The scientists showed how they succeeded in externally steering such a high-density solution through different courses.

Once the microrobots are accumulated at the desired point (the tumor spheroid), a near infrared laser generates rays with temperatures of up to 55 degrees Celsius, triggering a melting process of the liposome and a release of the enclosed drugs. A low pH level or acidic environment also causes the nanoliposomes to break open—hence the drugs are released near a tumor automatically.

Bacteria-based biohybrid microrobots with medical functionalities could one day battle cancer more effectively. It is a new therapeutic approach not too far away.

Mukrime Birgul Akolpoglu et al, Magnetically steerable bacterial microrobots moving in 3D biological matrices for stimuli-responsive cargo delivery, Science Advances (2022). DOI: 10.1126/sciadv.abo6163. www.science.org/doi/10.1126/sciadv.abo6163

Comment by Dr. Krishna Kumari Challa on July 15, 2022 at 11:28am

Watch this shape-shifting magnetic material catch a ball on command

Printable iron-laced substance is programmed by computer to make precise, rapid movements.

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